Number stories with bigger numbers work in the same way as small ones. Decide if amounts are joined, taken away or compared, then choose your method.
For bigger numbers, use the column method or a number line. Round the numbers to estimate first so you know roughly what the answer should be. If a school has 643 children and 278 go on a trip, about 600 − 300 = 300 stay, and the exact answer is 365.
Worked example
Leo has 427 stamps. Mia has 186 stamps. How many more stamps does Leo have?
- Compare, so subtract: 427 − 186.
- Estimate 430 − 190 = 240. Exactly: 427 − 186 = 241.
Answer:241 more stamps
Key words
- estimate
- a rounded answer to check with
- exact
- the precise answer
- compare
- find how many more or fewer
Practise this
New questions every time.
Common Core-referenced: 3.NBT.A.2