Subtraction Strategies
Year 4 students use efficient mental and written strategies to subtract numbers, including counting up, compensation, and decomposition.
What You Need to Know
Key Concept Diagram
Counting up (shopkeeper method): find the difference by adding up from the smaller to larger number
Compensation: round and adjust, e.g. 83−29 → 83−30+1=54
Decomposition breaks numbers into place values for column subtraction
Checking by adding the answer to the subtracted number should give the original
Key Vocabulary
Subtraction
Finding the difference between two numbers
Difference
The result of subtracting one number from another
Decompose
Break a number into its place value parts
Compensation
Round a number then adjust the answer accordingly
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
83 − 29 = ?
Question 2
500 − 278 = ?
Question 3
Check: 95 − 37 = 58. How do you verify this?
Key Concepts Summary
- ●Counting up (shopkeeper method): find the difference by adding up from the smaller to larger number
- ●Compensation: round and adjust, e.g. 83−29 → 83−30+1=54
- ●Decomposition breaks numbers into place values for column subtraction
- ●Checking by adding the answer to the subtracted number should give the original