# Rounding

Rounding to 10

When you are rounding a number to the nearest 10, you are trying to find out which multiple of 10 your number is closest to.

The golden rule with rounding is that if a number is exactly halfway between two multiples of 10, you always round up.

How to round a number to the nearest 10

Look at the ones digit.

• if it is less than 5 then round the number down by changing the ones digit to zero;
• if it is 5 or more then round the number up by adding one on to the tens digit and changing the ones digit to zero.

Examples

• 37 rounds up to 40 because the ones digit is 7.
• 63 rounds down to 60 because the ones digit is 3.
• 145 rounds up to 150 because the ones digit is a 5.

Rounding to 100

When you are rounding a number to the nearest 100, you are trying to find out which multiple of 100 your number is closest to.

How to round a number to the nearest 100

Look at the tens digit.

• if it is less than 5 then round the number down by changing the tens digit and ones digit to zero;
• if it is 5 or more then round the number up by adding one on to the hundreds digit and changing the tens and ones digit to zero.

Examples

• 287 rounds up to 300 because the tens digit is 8.
• 1629 rounds down to 1600 because the tens digit is 2.
• 950 rounds up to 1000 because the tens digit is a 5.

Rounding to 1000

When you are rounding a number to the nearest 1000, you are trying to find out which multiple of 1000 your number is closest to.

How to round a number to the nearest 1000

Look at the hundreds digit.

• if it is less than 5 then round the number down by changing the hundreds, tens and ones digits to zero;
• if it is 5 or more then round the number up by adding one on to the thousands digit and changing the hundreds, tens and ones digits to zero.

Examples

• 4687 rounds up to 5000 because the hundreds digit is 6.
• 8296 rounds down to 8000 because the hundreds digit is 2.
• 11583 rounds up to 12000 because the hundreds digit is a 5.

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