To find the overall discount on two differently priced items, calculate each saving in dollars. Add the savings and divide by the combined original price. The two discount percentages refer to different amounts, so averaging them can give the wrong result.
MOE’s Primary Six Mathematics syllabus covers percentage increase and decrease. The examples below use two items bought together and show how to check the result against the total paid.
- Use each item’s own original price to find its saving.
- Add the savings in dollars.
- Compare the total saving with the combined original price.
Worked example | 25% off a bag and 10% off shoes
A bag originally costs $80 and is discounted by 25%. Shoes originally cost $120 and are discounted by 10%. What percentage of the original combined price does the shopper save?
The bag saves 25% of $80 = $20. The shoes save 10% of $120 = $12. Together the shopper saves $32 on an original total of $200. The overall discount is 32 ÷ 200 × 100% = 16%.
Check using the sale prices. The bag costs $60 and the shoes cost $108. The total paid is $168. Since $200 − $168 = $32, the saving matches the earlier calculation.
When does a simple average work?
If both items originally cost $100, a 25% discount saves $25 and a 10% discount saves $10. The total saving is $35 out of $200, or 17.5%, exactly the average of the two rates. The original amounts have equal weight.
In the worked example, the shoes account for more of the original total and have the lower discount. That pulls the combined rate closer to 10% than to 25%. Check that the overall rate lies between the two item rates when both original prices are positive.
Try two items that save the same number of dollars
One item costs $60 before a 20% discount. Another costs $40 before a 30% discount. Each saves $12. The combined saving is $24 out of $100, so the overall discount is 24%.
A parent can ask whether the question wants the total saving, the total paid or the percentage saving. In this example the answers are $24, $76 and 24% respectively.
Frequently asked questions
Why divide by the original total?
The percentage discount compares the saving with what the items cost before the discounts.
What if one item has no discount?
Include its original price and count its saving as zero if it belongs to the purchase in the question.
Official information
MOE’s 2021 Primary Mathematics syllabus, October 2025 update, Primary Six Percentage. Checked 10 November 2026.