Quick answer: Primary 3 Mathematics introduces equivalent fractions, simplifying fractions, comparing unlike fractions and adding or subtracting fractions with related denominators. Children need to understand that 1/2, 2/4 and 3/6 are the same amount even though their numerators and denominators differ. This guide explains 200 useful words and phrases with fraction strips, number-line reasoning, worked examples, common errors and a four-week revision plan.
The MOE 2021 Primary Mathematics syllabus updated October 2025 covers equivalent fractions and simplest form, comparing fractions and related-denominator operations at P3. The stated learning outcomes set boundaries on given denominators and work with fractions within one whole. Mixed numbers and multiplication of fractions are developed later, so they are not presented here as independent new P3 outcomes. This is an explanatory word bank, not a list of 200 official examinable words.
Jump to a section:
- All 200 fraction vocabulary terms
- Twelve worked equivalent-fraction and fraction-operation examples
- How to diagnose common fraction mistakes
- A four-week P3 fractions learning plan
- FAQs and next reading
Top 200 Primary 3 fraction words and phrases
The entries are arranged by what a learner must do: name the whole, read the notation, draw an equal partition, rename equivalent fractions, simplify and compare, then perform the correct operation. Phrases as well as single words are included because school questions ask pupils to explain a relationship, not just repeat definitions.
1. Understanding one whole and its equal parts (words 1–20)
- whole — The complete quantity used as the reference for a fraction.
- part — A portion of the chosen whole.
- equal parts — Pieces having the same amount or size.
- fraction — A number describing equal parts of a whole.
- share — A quantity allotted from the complete amount.
- half — One of two equal parts.
- third — One of three equal parts.
- quarter — One of four equal parts.
- fifth — One of five equal parts.
- sixth — One of six equal parts.
- eighth — One of eight equal parts.
- tenth — One of ten equal parts.
- twelfth — One of twelve equal parts.
- unit fraction — One single equal part of a whole.
- proper fraction — A positive fraction whose numerator is smaller than its denominator.
- fraction of one whole — A fraction understood relative to one complete unit.
- reference whole — The particular complete amount to which a fraction refers.
- same-sized wholes — Complete units of equal size that can be compared fairly.
- different-sized wholes — Units whose fractional pieces may have different actual sizes.
- fractional amount — A quantity represented as a part of the named whole.
2. Reading numerators and denominators (words 21–40)
- numerator — The number above the fraction bar counting selected equal parts.
- denominator — The number below the bar indicating the size of the equal partition.
- fraction bar — The horizontal line separating numerator and denominator.
- top number — A friendly name for the numerator before introducing formal terminology.
- bottom number — A friendly name for the denominator.
- one over two — The spoken form of 1/2.
- one over three — The spoken form of 1/3.
- two over three — The spoken form of 2/3.
- one over four — The spoken form of 1/4.
- three over four — The spoken form of 3/4.
- two over five — The spoken form of 2/5.
- three over five — The spoken form of 3/5.
- four over five — The spoken form of 4/5.
- five over six — The spoken form of 5/6.
- three over eight — The spoken form of 3/8.
- seven over eight — The spoken form of 7/8.
- two over ten — The spoken form of 2/10.
- five over ten — The spoken form of 5/10.
- six over twelve — The spoken form of 6/12.
- fraction in numerals — A fraction represented with its numbers and bar rather than written in words.
3. Drawing and building fraction models (words 41–60)
- fraction strip — A bar divided into equal sections representing fractional parts.
- fraction circle — A circular figure split into equal sectors.
- fraction rectangle — A rectangular region partitioned into equal fractional areas.
- equal-area pieces — Sections covering the same amount of surface.
- folding in half — Making two equal sections by placing edges together.
- folding in quarters — Creating four equal sections of one strip.
- shade the fraction — Colour exactly the sections named by the numerator.
- unshaded remainder — The part left uncoloured in a fractional diagram.
- label each piece — Write the unit fraction represented by one section.
- draw the whole first — Begin with the complete reference figure before dividing.
- horizontal partition — A division using lines across the width of a figure.
- vertical partition — A division using lines along the height of a figure.
- grid model — A set of equal small boxes for representing fractions.
- number-line fraction — A fraction shown at a position on a number line.
- zero point — The number line position representing zero.
- one point — The point representing one whole unit.
- equal intervals — Number-line spaces of the same length.
- partition a number line — Divide the interval from zero to one into equal parts.
- move to three quarters — Advance three equal quarter-length intervals from zero.
- model a comparison — Draw fractions of identical reference wholes to compare amounts.
4. Equivalent fraction language (words 61–80)
- equivalent fractions — Different fractional numerals representing the same amount.
- equal fraction value — Two fractions that refer to the same numerical size.
- rename a fraction — Express a value using a different numerator and denominator.
- same shaded region — A fraction model whose total coloured area is unchanged.
- more smaller pieces — A finer partition giving additional parts without changing the value.
- same total area — The property preserved when each original fractional section is subdivided.
- split each part equally — Create an equivalent fraction by subdividing every unit piece.
- double numerator and denominator — Multiply the top and bottom by two without changing value.
- triple numerator and denominator — Multiply both fraction parts by three to create an equivalent name.
- multiply both parts equally — Use the same non-zero scale factor on numerator and denominator.
- divide both parts equally — Reduce numerator and denominator by a common positive factor.
- fraction scale factor — The number used on both parts to create an equivalent representation.
- one half equals two quarters — A basic equality of 1/2 and 2/4.
- one half equals three sixths — A basic equality of 1/2 and 3/6.
- one third equals two sixths — A basic equality of 1/3 and 2/6.
- two thirds equals four sixths — A basic equality of 2/3 and 4/6.
- one quarter equals two eighths — A basic equality of 1/4 and 2/8.
- three quarters equals six eighths — A basic equality of 3/4 and 6/8.
- four eighths equals one half — A fraction reduced to an equivalent unit fraction.
- equivalence check — Compare with a drawing or multiplication to confirm equal value.
5. Simplifying fractions to simplest form (words 81–100)
- simplify a fraction — Write the same value using a reduced numerator and denominator.
- simplest form — A fraction whose numerator and denominator have no common factor above one.
- lowest terms — Another name for simplest form.
- common factor — A whole number that divides numerator and denominator exactly.
- shared divisor — A number by which both numerator and denominator can be divided.
- divide numerator and denominator — Apply the same non-zero division to both to preserve value.
- common factor of two — A shared factor allowing top and bottom to be halved.
- common factor of three — A shared factor allowing both fraction parts to be divided by three.
- common factor of four — A shared factor allowing a fraction to be reduced by four.
- common factor of six — A shared factor allowing division of both parts by six.
- six eighths reduced — The equality 6/8 = 3/4.
- four sixths reduced — The equality 4/6 = 2/3.
- three ninths reduced — The equality 3/9 = 1/3.
- six tenths reduced — The equality 6/10 = 3/5.
- eight twelfths reduced — The equality 8/12 = 2/3.
- common-factor list — A systematic list of whole numbers dividing both fraction parts.
- reduce step by step — Simplify repeatedly using available common factors.
- reduce in one step — Use a sufficiently large common factor to reach simplest form directly.
- unchanged fractional value — The amount preserved when a fraction is simplified.
- confirm lowest terms — Check that no shared divisor greater than one remains.
6. Comparing fractions with familiar landmarks (words 101–120)
- fraction comparison — Determine whether one fraction is larger, smaller or equal to another.
- larger fraction — A fraction with the greater numerical value.
- smaller fraction — A fraction with the lesser numerical value.
- equal fractions — Different or identical numerals representing the same value.
- fraction benchmark — A familiar quantity, often one half, used for comparison.
- one-half benchmark — The reference fraction 1/2.
- below one half — A fractional amount smaller than 1/2.
- equal to one half — A fractional amount identical in value to 1/2.
- above one half — A fractional amount larger than 1/2.
- near one whole — A proper fraction with value close to one.
- one whole minus a part — The distance from a fraction to the complete unit.
- same numerator — Fractions whose top numbers match.
- same denominator — Fractions whose bottom numbers match.
- unit fraction comparison — A comparison of fractions with numerator one.
- like fraction comparison — Compare numerators when denominators are equal.
- unlike fraction comparison — Compare fractions with different denominators by equivalent parts.
- number-line position — The point showing the fraction’s size along a unit interval.
- right of on number line — A fraction to the right has the greater value.
- left of on number line — A fraction to the left has the smaller value.
- justify the ordering — Explain the comparison using equal pieces or a common reference.
7. Common denominators and related partitions (words 121–140)
- like denominators — Matching denominators representing the same-sized parts.
- unlike denominators — Different denominators representing different part sizes.
- common denominator — One denominator usable for two equivalent fraction names.
- related denominators — Denominators where one is a multiple of the other.
- double partition — A division into twice as many equal pieces.
- triple partition — A division into three times as many equal pieces.
- quarter-to-eighth conversion — Rename one quarter as two eighths.
- half-to-quarter conversion — Rename one half as two quarters.
- half-to-sixth conversion — Rename one half as three sixths.
- third-to-sixth conversion — Rename one third as two sixths.
- third-to-twelfth conversion — Rename one third as four twelfths.
- quarter-to-twelfth conversion — Rename one quarter as three twelfths.
- sixth-to-twelfth conversion — Rename one sixth as two twelfths.
- same fraction units — Both quantities expressed as equal-sized named parts.
- make the parts comparable — Rename fractions before adding or subtracting them.
- common-part model — A strip where both fractions are drawn using one partition.
- numerator after renaming — The adjusted count of equal parts in an equivalent fraction.
- denominator after renaming — The adjusted number of equal sections in the whole.
- equivalent before operating — Rewrite values to a shared part size before calculation.
- denominator not exceeding twelve — A syllabus boundary for given fractions in the P3 topic.
8. Adding related and like fractions (words 141–160)
- fraction addition — Combining fractional amounts of a common whole.
- add like fractions — Add selected part counts when denominator is the same.
- add related fractions — Use equivalent fractions to combine parts with related denominators.
- sum of fractions — The amount found from fractional addition.
- combine shaded sections — Find the total coloured part of one whole.
- two eighths plus three eighths — The result 5/8 from combining equal eighth-parts.
- one quarter plus one eighth — The result 3/8 after expressing a quarter as two eighths.
- one half plus one quarter — The result 3/4 using four equal quarter-parts.
- one third plus one sixth — The result 1/2 after combining two sixths and one sixth.
- two thirds plus one sixth — The result 5/6 after renaming two thirds as four sixths.
- same reference whole for addition — Both fractions describe portions of one equally sized unit.
- sum within one whole — An addition whose answer is no greater than one complete unit.
- draw the combined fraction — Shade the two added portions without overlapping them twice.
- count selected equal parts — Add numerator counts after the part sizes match.
- denominator stays the unit — The denominator names part size rather than a second count to add.
- equivalent fraction in the sum — A renamed value used to prepare addition.
- numerator sum — The combined count of selected equal-size parts.
- fraction answer label — A statement describing what portion of the whole was combined.
- reduce the final sum — Simplify an equivalent result if a common factor remains.
- addition check by picture — Count shaded cells on a fraction model to verify the sum.
9. Subtracting fractions and understanding what remains (words 161–180)
- fraction subtraction — Removing one fractional amount from another.
- take a fractional part away — Remove a stated number of equal pieces from selected parts.
- fraction difference — The numerical result of subtracting fractional amounts.
- fraction remaining — The equal-part amount still present after removal.
- unshaded part — The portion of the original whole not selected or coloured.
- whole minus fraction — Subtract a fractional portion from one complete unit.
- three quarters minus one quarter — The result 1/2 after removing one quarter from three quarters.
- five sixths minus one third — The result 1/2 after renaming one third as two sixths.
- seven eighths minus three eighths — The result 1/2 when four eighths remain.
- three quarters minus one half — The result 1/4 after converting one half to two quarters.
- one whole minus three eighths — The remaining 5/8 of the unit.
- two thirds minus one sixth — The result 1/2 after expressing two thirds as four sixths.
- common-part subtraction — Subtract pieces after both fractions use the same denominator.
- cross out fraction pieces — Mark removed equal sections on a drawn model.
- remaining equal sections — The parts still selected after subtracting.
- start fraction — The portion held before a removal.
- removed fraction — The portion taken from the starting amount.
- same unit for both quantities — A requirement that the fractions refer to compatible wholes.
- subtract numerators after conversion — Subtract selected piece counts once denominators match.
- verify by adding back — Add the difference to the removed fraction to recover the start.
10. Fraction word problems and checking strategies (words 181–200)
- fraction of a ribbon — A length represented as a share of the complete ribbon.
- fraction of a cake — A portion of one whole cake cut into equal pieces.
- fraction of a chocolate bar — A share of a single complete bar.
- fraction of a coloured shape — The shaded part compared with the entire diagram.
- amount shaded — The fraction already coloured in a model.
- amount unshaded — The fraction left without colour.
- fraction used — The share consumed in the story.
- fraction left — The portion still available.
- two fractions from one whole — Parts that may be compared or combined when the wholes match.
- unlike-sized wholes — A warning that equal fraction names can describe different physical amounts.
- identify the whole first — Say exactly what one complete unit represents.
- check the partition — Confirm that all parts are equal before naming fractions.
- choose a fraction strip — Use a bar divided into suitable equal sections for comparison.
- choose a number line — Locate fractional values between zero and one.
- rename before comparing — Write fractions using equivalent parts to judge size.
- rename before adding — Create compatible equal parts before combining fractions.
- rename before subtracting — Create compatible equal parts before removing fractional quantities.
- check a result with one half — Use the familiar 1/2 reference to catch implausible comparisons.
- say why denominators remain — Explain that the part size was unchanged during like-fraction addition.
- answer with the whole named — State the fraction and the object it refers to.
Twelve worked P3 fraction examples with explanations
1. Two different fraction names can show one amount
Take a paper strip and fold it into two equal halves. Colour one half. Now fold each half once more, making four equal pieces. The coloured region covers 2/4, the same amount as 1/2. Repeat by dividing each half into three pieces: the coloured amount is 3/6. The number of pieces changed, but the shaded length did not. That is the meaning of equivalent fractions.
2. Multiply both parts to create an equivalent fraction
Find a fraction equivalent to 2/3 with denominator 12. Since 3 × 4 = 12, multiply both numerator and denominator by four: 2/3 = 8/12. The numerator changes from two to eight because each original third has been subdivided into four equal pieces. Check by drawing a bar divided into three large parts, then splitting each into four small parts.
3. Simplify without changing the value
Simplify 8/12. Both eight and twelve can be divided by four. The new numerator is two and the new denominator is three, so 8/12 = 2/3. A strip with twelve cells shaded in eight positions can be regrouped into three equal blocks, with two shaded blocks. This shows that simplifying changes the fraction’s name rather than removing part of its value.
4. A common factor explains simplest form
Reduce 6/10. Both numerator and denominator are divisible by two: 6 ÷ 2 = 3 and 10 ÷ 2 = 5. Therefore the simplest form is 3/5. The new numerator and denominator have no common whole-number factor above one. A child who divides only the numerator gets 3/10, which is not equal to the original fraction. Ask what must be preserved during simplification.
5. Unit fractions reverse the easy whole-number comparison
Which is larger: 1/3 or 1/6? Divide two identical strips, one into three equal pieces and the other into six. A single third covers more length than a single sixth. Therefore 1/3 is larger than 1/6. The bigger denominator does not mean a bigger fraction when the numerator is one: more equal cuts create smaller pieces.
6. Like fractions can be ordered by their numerators
Compare 5/8 and 3/8. Both fractions use the same eighth-size pieces of one equally sized whole. Five eighths contains two more eighth-pieces than three eighths, so 5/8 is larger than 3/8. The denominator stays the unit, and the numerator counts how many of those units are selected. A number-line diagram places 5/8 to the right of 3/8.
7. Unlike fractions need a shared reference
Compare 2/3 with 3/4. Rename both in twelfths: 2/3 = 8/12 and 3/4 = 9/12. Since nine twelfths is larger than eight twelfths, 3/4 is larger. For a learner who finds the symbolic calculation hard, draw two identical rectangles divided into twelve equal cells and shade eight and nine respectively. The comparison then becomes a count of equal-size parts.
8. One half is a useful benchmark
Is 5/12 smaller or larger than 1/2? One half of twelve equal parts is six parts, or 6/12. Since five twelfths is less than six twelfths, 5/12 is below one half. Is 7/12 above one half? Yes, by one twelfth. Benchmark comparisons can often be solved with a small diagram instead of finding a long sequence of equivalent fraction names.
9. Add like fractions without adding their denominators
A ribbon has 2/8 of its length coloured blue and 3/8 coloured red. The total coloured length is 2/8 + 3/8 = 5/8. The whole ribbon is still divided into eighths. Adding the denominators would produce sixteenths, which would change the size of the pieces without justification. Draw eight equal boxes to see why the denominator remains eight.
10. Add related fractions after renaming them
Find 1/4 + 1/8. Rename the quarter as 2/8. Now the sum is 2/8 + 1/8 = 3/8. The drawing must show the same reference whole and eight equal-size parts. This is the role of a common denominator: it names the kind of piece being counted. The numerical operation becomes straightforward only after the pieces have matching size.
11. Subtract fractions using the same type of part
Find 5/6 − 1/3. One third is equivalent to two sixths, so 5/6 − 2/6 = 3/6 = 1/2. Begin by colouring five of six cells, then cross out two cells. Three remain shaded. Check with 1/2 + 1/3 = 3/6 + 2/6 = 5/6. The inverse addition confirms the answer’s value.
12. A fraction story must name its whole
One child eats 1/2 of a small cake while another eats 1/3 of a larger cake. Does the first child necessarily eat more cake by mass or volume? No. The cake sizes are different, so the fractions describe shares of different wholes. If both cakes were identical, then 1/2 is larger than 1/3. Ask pupils to identify the reference whole before comparing fractional portions from different objects.
What makes a fraction equivalent, rather than merely similar?
Two fractions are equivalent when their numerical values are identical. They may use different numerator and denominator pairs, but multiplying both parts by the same non-zero value or dividing both parts by a common non-zero factor preserves the value. A diagram can make this visible: the selected portion remains the same while the partition becomes finer or coarser.
A common error is to divide only the numerator or only the denominator during simplification. For example, replacing 6/10 with 3/10 halves the selected count but leaves the piece size unchanged, so it halves the value. Replacing 6/10 with 3/5 divides both numbers by two; it changes the piece size and selected count in a coordinated way so the same share is represented.
Why the reference whole matters in word problems
A fraction tells us about a portion relative to a particular complete amount. One half of a tiny chocolate bar may be physically smaller than one third of a much larger bar. In a P3 question showing two shaded diagrams, first confirm that the two complete figures are comparable and that their partitions are equal. A child who can identify the whole is less likely to compare numerators or denominators mechanically.
The same issue appears with number-line fractions. The interval from zero to one represents a whole unit; the positions one half, two thirds and three quarters are meaningful because the same unit length is being used. If one number line uses longer unit spacing than another, the drawings cannot be compared by raw centimetres on paper without paying attention to their labelled scale.
Ten misconceptions and simple repairs
- Unequal pieces called quarters: fold paper so that every part is the same length or area.
- Numerator and denominator reversed: ask how many selected parts and how many parts make one whole.
- Thinks 1/8 is greater than 1/4 because eight is bigger: compare single pieces of identical strips.
- Divides only one fraction part: model equivalence and apply the same non-zero factor to numerator and denominator.
- Stops before simplest form: test both numbers for another common factor.
- Compares unlike fractions without common parts: rename using a shared denominator or use a benchmark.
- Adds denominators together: keep the named piece size fixed and add the selected piece counts.
- Subtracts unrelated part sizes: convert the fractions before removing pieces.
- Mixes fractions from different-sized wholes: label the unit and compare equivalent reference wholes first.
- Writes an answer but cannot explain it: ask for a fraction strip or number-line model with the same value.
A parent-friendly diagnostic with twelve quick questions
- 1/2 equals how many quarters? 2/4.
- 1/3 equals how many sixths? 2/6.
- 2/3 equals how many twelfths? 8/12.
- 6/10 in simplest form is 3/5.
- 8/12 in simplest form is 2/3.
- Which is greater, 1/4 or 1/8? 1/4.
- Which is greater, 4/9 or 7/9? 7/9.
- Which is greater, 3/4 or 2/3? 3/4.
- 2/8 + 3/8 = 5/8.
- 1/2 + 1/4 = 3/4.
- 5/6 − 1/3 = 1/2.
- 1 − 3/8 = 5/8.
The numbers are not the whole assessment. Ask the child to show the comparison in a model, explain why parts can be combined and describe whether the reference whole stays the same. A pupil who can justify the answer in an unfamiliar diagram has a stronger foundation for P4 work.
How to move from picture models to independent fraction reasoning
Begin with equal-length paper strips. Ask the child to fold, colour and describe. Then give two drawn fraction strips and ask which is larger. Next remove the diagrams and provide only the fractional numerals; the pupil can draw a model if needed. Finally ask the pupil to create a new story where the same fraction comparison or sum occurs. This sequence supports reasoning, not merely speed.
As children become more fluent, encourage efficient choices. If both fractions have denominator eight, compare their numerators. If one denominator doubles the other, rename the coarser fraction into the finer units. If both fractions are close to half, use the half benchmark as a quick check. Choosing a shorter valid method is part of mathematical competence.
Four-week P3 fraction vocabulary and practice plan
Week 1 — Parts, wholes and fraction notation
Fold identical strips into halves, thirds, quarters, sixths and eighths. Write fractions and read them aloud. Identify numerator, denominator and the reference whole. Practise locating simple fractions between zero and one.
Week 2 — Equivalent fractions and simplest form
Subdivide a shaded strip into smaller equal pieces without changing shaded length. Write equivalent names, then reverse the process by reducing fractions to simplest form. Ask the child to explain why numerator and denominator change together.
Week 3 — Compare unlike fractions
Start with like denominators, then unit fractions. Use one half as a benchmark before moving to fractions with related denominators. Compare two equal strips first, then practise symbolic renaming.
Week 4 — Addition, subtraction and word problems
Combine and remove like fractions before related-denominator fractions. Keep examples within one whole and ensure equal reference units. Mix familiar and changed stories without announcing which operation is required. Revisit incorrect models after a day or two.
Preparing for P4 without teaching topics prematurely
The next year extends fraction understanding to mixed numbers, improper fractions and fractions of sets. A child who already understands equivalence, whole units and common part sizes will have a clearer reason for later procedures. It is often more effective to strengthen these P3 ideas than to race into larger numerical expressions without a stable concept of the whole.
When a pupil says “1/2 is the same as 2/4 because each of the two pieces was split into two”, that explanation reveals understanding. When a pupil simply writes “times two” beside the numerator and denominator without identifying what stayed the same, ask for a picture and a real example. The purpose of mathematical language is to make reasoning visible.
Frequently asked questions
Does P3 include equivalent fractions and simplest form?
Yes. The updated Primary 3 syllabus includes identifying equivalent fractions, expressing fractions in simplest form and comparing fractions, including unlike fractions.
Do P3 children need mixed numbers?
Mixed numbers and improper-fraction work are formally developed in P4. Concentrate on accurate understanding of proper fractions and equivalence at P3.
Can children compare fractions without finding a common denominator?
Yes, in suitable cases. Like denominators, unit fractions, common benchmarks and models can support a comparison. A common denominator is one reliable method, not the only valid explanation.
Should pupils memorise the 200 words?
No. The glossary includes mathematical phrases and examples for understanding. Use a manageable subset at a time and apply the words to a drawing or problem.
How do I correct “add the denominator” mistakes?
Show both fractions using the same complete strip divided into equal parts. Explain that the denominator is the size-name of those parts, while the numerator counts selected pieces.
Official source and connected reading
Consult the MOE Primary Mathematics syllabus updated October 2025. Continue with eduKate’s P3 full Mathematics vocabulary guide, P2 fractions and mathematics vocabulary foundation and P3 word-problem reading guide. This subject-specific fraction article is an independent explanation and does not claim to reproduce official questions.
