Estimate Differences: Word Problems in Estimate & Check
30 October 2026
When your child faces a subtraction word problem, it can be helpful to estimate the answer before working it out exactly. Estimating differences gives children a quick way to check if their final answer is sensible.
Example question
A farmer has 248 apples and sells 129 apples. Estimate how many apples are left, then check your answer.
Step 1: Round each number to the nearest ten.
248 rounds to 250.
129 rounds to 130.
Step 2: Subtract the rounded numbers. 250 - 130 = 120
Step 3: Work out the exact difference. 248 - 129 = 119
Step 4: Check if your estimate is close to the real answer.
120 is close to 119, so your calculation makes sense.
Key insight: Estimating by rounding helps you check if your answer is reasonable.
The farmer has about 120 apples left after selling 129 apples.
Click or tap on the number line to answer
After working through this example, your child will see how rounding and subtracting can make word problems easier to handle. They will also know how to use estimate & check to spot mistakes and build confidence with similar questions.
