To round to the nearest 1000, 10 000 or 100 000, find the two multiples the number sits between, then look at the deciding digit: the one just right of the rounding place. If it is 5 or more, round up; if it is less than 5, round down. Every digit after the rounding place becomes 0. Look at the deciding digit only once: do not round one place at a time.
Explore this idea with maths tools
Maths you can move
Build 8 + 5
Tap two gold counters to fill the ten-frame.
8 in the frame + 5 waiting. The total stays the same.
Words to know
- round
- replace a number with the nearest simpler one
- deciding digit
- the digit just right of the rounding place
Worked examples
4682 is between 4000 and 5000. Round it to the nearest 1000.
- 1.The deciding digit is the hundreds digit, 6.
- 2.6 is 5 or more, so round up.
= 5000
Round 3 449 612 to the nearest 100 000.
- 1.It is between 3 400 000 and 3 500 000.
- 2.The deciding digit is the ten thousands digit, 4, so round down.
= 3400000
Round 49 700 to the nearest 1000.
- 1.It is between 49 000 and 50 000. The deciding digit is 7, so round up.
- 2.49 thousands + 1 thousand = 50 thousands.
= 50000
For parents
Method: Look at the deciding digit
What to say: Which two numbers is it between? What is the deciding digit?
Common mistakes:
- Always rounds down by cutting off the lower digits, whatever the deciding digit.
- Always rounds up to the next multiple, even when the deciding digit is less than 5.
- Rounds one place at a time from the right, which can push the number up (4482 → 4480 → 4500 → 5000).
- Rounds to the place one column too small (to the nearest 100 instead of 1000).
- Changes the rounding digit but keeps the digits after it instead of making them zero (4682 → 5682).