The note
How schools teach it now
Children look at the digit just to the right of the place they're rounding to: 5 or more rounds up, 4 or less stays. Number lines help: 3,672 lies between 3,600 and 3,700 and is nearer 3,700.
5-minute kitchen-table activity
In the supermarket, round each item to the nearest pound and keep a running total in your heads. At the till, compare with the real total. Who was closest?
Worked example
Round 7.846 to one decimal place.
- One decimal place means tenths: the answer is 7.8 or 7.9.
- Look at the next digit, the hundredths: it's 4.
- 4 is less than 5, so round down.
Answer: 7.8
Common mistakes to watch for
- Looking at the last digit instead of the next one along.
- Rounding 7.96 to one decimal place as 7.10 (it's 8.0).
- Dropping zeros: 3,672 to the nearest hundred is 3,700, not 37.
Encouragement
- Try saying
- “Which two numbers is it between? Which one is it nearer?”
- Rather than
- “Just knock the end off.”