An **approximation** is anything that is similar, but not exactly equal, to something else. A number can be approximated by rounding. A calculation can be approximated by rounding the values within it before performing the operations.

To approximate to the nearest ten, look at the digit in the **tens column**.

To approximate to the nearest hundred, look at the digit in the **hundreds column**.

For the nearest thousand, look at the digit in the **thousands column**.

Then do the following:

- draw a vertical line to the right of the place value digit that is required
- look at the next digit
- if it's
**5 or more**, increase the previous digit by one - if it's
**4 or less**, keep the previous digit the same - fill any spaces to the
**right**of the line with zeros

**Round 4,853 to the nearest 10, 100 and 1,000.**

- 485|
**3**to the nearest 10 is 4,850 - 48|
**5**3 to the nearest 100 is 4,900 - 4|
**8**53 to the nearest 1,000 is 5,000

**Round 76,982 to the nearest 10, 100 and 1,000.**

- 7698|
**2**to the nearest 10 is 76,980 - 769|
**8**2 to the nearest 100 is 77,000 - 76|
**9**82 to the nearest 1,000 is 77,000

Notice that in some cases the answers for rounding are the same.

Rounding to 100 required a slightly different technique in this instance. The number after the line was an 8, meaning that the number before the line needs to increase by one. Increasing a 9 to a 10 means putting a 0 in place of the 9 and adding an extra 1 to the next column along.

- Question
What is 9,538 rounded to the nearest 10, 100 and 1,000?

- 953|
**8**to the nearest 10 is 9,540 - 95|
**3**8 to the nearest 100 is 9,500 - 9|
**5**38 to the nearest 1,000 is 10,000

- 953|

- Question
What is 89,555 rounded to the nearest 10, 100 and 1,000?

- 8955|
**5**to the nearest 10 is 89,560 - 895|
**5**5 to the nearest 100 is 89,600 - 89|
**5**55 to the nearest 1,000 is 90,000

- 8955|