Rounding Numbers



To do this topic, you need to know place values.
To review the Place Value topic, see here.

Rounding numbers is a way to estimate numbers.
To round numbers,

Step 1: What are you rounding to?
Look at the digit to the right of the place you are rounding to.
Round to the nearest ten? Look at the digit in the ones place.
Round to the nearest hundred? Look at the digit in the tens place.

Step 2: Round up or round down?


Example 1: Round to the nearest ten

1.   68
Since we are rounding to the nearest ten, we look at the digit in the ones place.
The digit in the ones place is 8.
So we round 68 up to 70.

2.   213
Since we are rounding to the nearest ten, we look at the digit in the ones place.
The digit in the ones place is 3.
So we round 213 down to 210.

3.   498
Since we are rounding to the nearest ten, we look at the digit in the ones place.
The digit in the ones place is 9.
So we round 498 up to 500.


Example 2: Round to the nearest thousand

1.   1500
Since we are rounding to the nearest thousand, we look at the digit in the hundreds place.
The digit in the hundreds place is 5.
So we round 1500 up to 2000.

2.   1499
Since we are rounding to the nearest thousand, we look at the digit in the hundreds place.
The digit in the hundreds place is 4.
So we round 1499 down to 1000.

3.   9503
Since we are rounding to the nearest thousand, we look at the digit in the hundreds place.
The digit in the hundreds place is 5.
So we round 9503 up to 10000.

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