Skill: Round numbers to the nearest 100

To round a whole number to the nearest $100$, find the two multiples of $100$ that the number lies between. Then decide which hundred is closer.

• If the last two digits are from $00$ to $49$, round down.
• If the last two digits are from $50$ to $99$, round up.

Example: Round $647$ to the nearest $100$

1. Find the hundreds it is between:
   $647$ lies between $600$ and $700$.

2. Look at the last two digits:
   The last two digits are $47$.

3. Compare $47$ with $50$:
   Since $47$ is less than $50$, $647$ is closer to $600$ than to $700$.

4. Write the rounded number:

$$647 \approx 600$$

So, $647$ rounded to the nearest $100$ is $600$.