Ontario · Grade 3
G3.B2.4
Grade 3 — Demonstrate an understanding of algorithms for adding and subtracting whole numbers.
The 2 skills that cover it
- AdditionAdd whole numbers fluently, from single-digit facts to multi-digit sums with regrouping. Addition means combining amounts.Read the lesson →
- SubtractionSubtract whole numbers, including borrowing across zeros, and recognise the three stories subtraction tells: take away, compare, and find the missing part.Read the lesson →
What a student should be able to do
- Recall addition facts within 20 automatically.
- Add multi-digit numbers using place value and regrouping.
- Add three or more numbers by looking for friendly pairs that make ten.
- Choose addition to solve "how many altogether" word problems.
- Recall subtraction facts within 20 automatically.
- Subtract multi-digit numbers with regrouping, including across zeros.
- Use addition to check a subtraction result.
- Choose subtraction for "how many are left" and "how many more" problems.