From facts to borrowing
- Within 10 and 20. Subtraction facts, like 13 – 5, a whole sheet at a time.
- Two digits, no regrouping. Every top digit is big enough: subtract the ones, then the tens.
- Two digits with regrouping. When the top ones digit is smaller, take one ten and make ten more ones.
- Three digits. The same steps across tens and hundreds.
Check by adding
Every subtraction has an addition hiding in it: if 72 – 38 = 34, then 34 + 38 = 72. Children who check their answers this way catch their own mistakes and learn how the two operations fit together. The addition worksheetsuse the same levels.
In the MOE curriculum
- Primary 1Subtracting within 100, including with the column method, and mental subtraction within 20.
- Primary 2Written subtraction for numbers up to 3 digits.
- Primary 3The column method reaches 4 digits, and children subtract 2-digit numbers mentally.
Where other countries say borrowing, Singapore’s syllabus says renaming: one ten is renamed as ten ones. Watch for the most common slip, taking the smaller digit from the bigger one whatever its place, as in 52 – 17 = 45. Asking “are there enough ones?” before each column stops it.
Subtraction also means comparing. In word problems, “how many more” and “how many fewer” are subtraction, and Singapore children draw them as a comparison model: two bars lined up, with the difference as the gap. Mixing a few such problems in alongside these sheets keeps that meaning alive.
Summarised in our own words from the MOE Primary Mathematics Syllabus (Primary One to Six, 2021, updated October 2025).
