Rounding to the Nearest Ten and Hundred

Rounding makes numbers easier to work with! When we round a number, we are finding a simpler number that is very close to the exact amount.

The Golden Rule of Rounding

To round a number, you always look at the digit one spot to the right of the place you want to round to.

Here is a fun rhyme to help you remember the rules:

• 4 or less, let it rest! (If the digit is $0, 1, 2, 3,$ or $4$, keep the number the same and change the rest to zeros.)
• 5 or more, let it soar! (If the digit is $5, 6, 7, 8,$ or $9$, round up by adding $1$ to your target number, and change the rest to zeros.)

Rounding to the Nearest Ten

When rounding to the nearest ten, find the digit in the tens place, then look right next door at the ones place.

Example: Round $3,562$ to the nearest ten.

1. Find the tens digit: It is $6$.
2. Look at the digit to the right (the ones place): It is $2$.
3. Apply the rule: Since $2$ is "4 or less," we let the $6$ rest.
4. Change the ones digit to a $0$.

Answer: $3,562$ rounded to the nearest ten is $3,560$.

Rounding to the Nearest Hundred

When rounding to the nearest hundred, find the digit in the hundreds place, then look right next door at the tens place.

Example: Round $847$ to the nearest hundred.

1. Find the hundreds digit: It is $8$.
2. Look at the digit to the right (the tens place): It is $4$.
3. Apply the rule: Since $4$ is "4 or less," let the $8$ rest.
4. Change the tens and ones digits to $0$.

Answer: $847$ rounded to the nearest hundred is $800$.

Example: Is $450$ closer to $400$ or $500$?

1. We are rounding to the nearest hundred. The hundreds digit is $4$.
2. Look to the right: The tens digit is $5$.
3. Apply the rule: "5 or more, let it soar!" We round up by changing the $4$ to a $5$.
4. Change the tens and ones to $0$.

Answer: Even though $450$ is right in the middle, the rule tells us to round up. So, it rounds to $500$!