Did you know? Half a pictogram symbol may stand for two whole objects. That makes a pictogram’s key just as important as its pictures. The same attention to scales and labels matters when reading a bar graph or a line graph.
Quick answer: Secondary 4 G1 Mathematics students should identify what was counted, read the pictogram key, interpret each axis and choose a suitable display. The 2027 SEC K110 syllabus includes pictograms, bar graphs, line graphs and dot diagrams as part of its data-handling content.
Example 1: a pictogram and its key
Imagine a fictional library pictogram where one book picture represents four books. Class A has three pictures, Class B has two-and-a-half pictures and Class C has one picture. The quantities are A: 3 × 4 = 12 books; B: 2.5 × 4 = 10 books; and C: 1 × 4 = 4 books.
The total is 26 books. Counting the pictures as 3, 2.5 and 1 gives the wrong result because the symbols are a scale, not literal books. Ask the learner what half a symbol means before calculating.
Example 2: a bar graph compares separate categories
Suppose 25 students each select one favourite activity. Twelve choose reading, eight choose sports and five choose music. A bar chart can display the three category counts, with a labelled vertical scale. The reading bar is highest, and the difference between reading and sports is 12 − 8 = 4 students.
A tutor should ask the student to check whether vertical gridlines go up in ones, twos or fives. Bar charts compare categories; their bars are commonly separated. Do not assume that one square on the graph always represents one person.
Example 3: a line graph shows a changing measurement
Imagine recorded temperatures of 28°C on Monday, 30°C on Tuesday, 27°C on Wednesday and 31°C on Thursday. A line graph across the four days makes the changes visible. The temperature drops by 3°C from Tuesday to Wednesday and is highest on Thursday.
The measurements above are invented for learning. Connecting four daily readings with lines does not mean every point between the readings was actually observed. It helps visualise an ordered pattern, not prove an event happened between measurement times.
Example 4: a dot diagram shows repetitions
Consider six results: 2, 3, 3, 5, 5, 5. Draw one dot above 2, two above 3 and three above 5. The diagram has six dots altogether, and the most frequent value is 5. The number of observations no greater than 3 is 3.
Dot diagrams are useful when the actual repeated numbers matter. For numerical values grouped into intervals, a histogram may tell the story more clearly.
A misleading scale can exaggerate a difference
Imagine two quantities of 6 and 8. They differ by just 2. If a bar chart begins its vertical axis at 5, the visible portions above the baseline measure 1 and 3. The second may look three times as tall even though the actual values are 8 and 6, a ratio of 4:3.
Always check where the axis starts. The numerical labels are evidence; the apparent height difference is only a visual impression.
A five-step reading routine
First read the title. Then read the key or legend. Next check the horizontal and vertical labels, including units and intervals. Count or calculate using the displayed scale. Finally, state the result in context: how many objects, which day, or what change?
What is covered in the SEC G1 Mathematics syllabus?
The official SEAB 2027 Mathematics K110 syllabus includes collecting and tabulating data, pictograms, bar graphs, line graphs, dot diagrams and judging advantages and limitations of statistical representations (S1). Statistics and Probability is tested in Paper 2, alongside Number and Algebra.
The 2027 SEAB G1 school-candidate listing names Mathematics as K110 and gives 4046 as the reference for 2026 and earlier. Check the candidate’s actual year and registered syllabus; these are original practice examples, not official examination questions.
A quick parent check
Ask: if one symbol represents four students, how many students do two-and-a-half symbols represent? The answer is 10. Next show two bars representing 6 and 8 and ask whether the second quantity is three times the first. It is not. Have the learner explain the scale rather than guess from the picture.
Close feedback helps a tutor distinguish misreading a key from calculating wrongly. The unchanged eduKateSG Clementi small-group Mathematics reference describes a three-pupil approach for Secondary 1; current Secondary 4 G1 lesson places, venues and timetables should be checked separately.
Frequently asked questions
Are pictograms part of G1 K110? Yes, along with bar charts, line graphs, dot diagrams and other displays.
What if the bars have a cut-off axis? Read the numerical scale before comparing quantities.
When is a line graph useful? When the order of measurements matters, such as comparing a measurement over successive days.
Continue with the other guides
Explore histograms and cumulative frequency, mean, median, mode and outliers and the G1 K110 examination plan.