# Rounding Whole Numbers

Sometimes we need to round whole numbers to the tens, hundreds etc.

For this we need to know place value of whole numbers.

Let's see how this can be done.

Example 1. Round 236 to the nearest ten.

Find tens in 236: 236. It is 3.

Look at the digit immediately to the right of 3: it is 6.

Since 6 is greater or equal than 5 then we increase 3 by 1 (resulting in 4) and change all digits to the right of 3 to zeros.

So, 236 rounded to ten is 240.

Next example.

Example 2. Round 234 to the nearest ten.

Find tens in 234: 234. It is 3.

Look at the digit immediately to the right of 3: it is 4.

Since 4 is less than 5 then we leave 3 and change all digits to the right of 3 to zeros.

So, 234 rounded to ten is 230.

Let's see how to round to the nearest hundred.

Example 3. Round 936 to the nearest hundred.

Find hundreds in 936: 936. It is 9.

Look at the digit immediately to the right of 9: it is 3.

Since 3 is less than 5 then we leave 9 and change all digits to the right of 9 to zeros.

So, 936 rounded to hundred is 900.

Next example.

Example 4. Round 5269 to the nearest hundred.

Find hundreds in 5269: 5269. It is 2.

Look at the digit immediately to the right of 2: it is 6.

Since 6 is greater or equal than 5 then we increase 2 by 1 (resulting in 3) and change all digits to the right of 2 to zeros.

So, 5269 rounded to hundred is 5300.

Let's see how to round to the nearest thousand.

Example 5. Round 936 to the nearest thousand.

Find thousands in 936: there is no thousand, but we can easily add it!

Write 936 as 0936 (remember that we can ignore leading zeros).

So, thousand is 0.

Look at the digit immediately to the right of 0: it is 9.

Since 9 is greater or equal than 5 then we increase 0 by 1 (resulting in 1) and change all digits to the right of 1 to zeros.

So, 936 rounded to thousand is 1000.

Final example is harder because we need to touch other digits as well.

Example 6. Round 4539827 to the nearest thousand.

Find thousands in 4539827: 4539827 It is 9.

Look at the digit immediately to the right of 9: it is 8.

Since 8 is greater or equal than 5 then we increase 9 by 1 (resulting in 10) and change all digits to the right of 9 to zeros.

As can be seen, we obtained 10 which is two-digit number. But we need one digit.

This situation is handled in following way: leave 0 and add remaining 1 to the digit immediately to the left: 3+1=4.

So, 4539827 rounded to thousand is 4540000.

In a similar manner we can round to any place: find digit on required place and examine the digit immediately to the right. If it is greater or equal than 5, increase found digit by 1 and change all digits to the right of this digit to zeros. Otherwise, leave found digit as it is and change all digits to the right of it to zeros.

Now, take a pen and paper and solve following problems.

Exercise 1. Round 156 to the nearest ten.

Next exercise.

Exercise 2. Round 23 to the nearest ten.

Next exercise.

Exercise 3. Round 13456 to the nearest hundred.

Next exercise.

Exercise 4. Round 234,523 to the nearest thousand.

Next exercise.

Exercise 5. Round 2944343 to the nearest million.