When we work some division problems, we can round the number we divide by to the nearest tens number. Here's a rule that will help us round in tens numbers: If the ones digit is 5 or more, round to the next tens number. Let's take the number 33 as an example.
The next tens number after 30 is 40. Here are some numbers in the 30s:
30 33 34 35 36 37 40
First, we round 33 to the nearest tens number. What's the ones digit in 33? The ones digit is 3. It's not 5 or more, so we don't round to the next tens number. We round 33 to 30.
Let's try 34. What's the ones digit in that number? The ones digit is 4. It's not 5 or more, so we round 34 to 30. Now, let's find out the nearest tens number for 36. Is the ones digit 5 or more? The ones digit is more than 5, so we round 36 to the next tens number, which is 40.
How about 37? Is the ones digit 5 or more? The ones digit is more than 5, so we round 37 to the next tens number, which is 40. Next we'll try 35. Remember, if the ones digit is 5 or more, we round to the next tens number. What do we round 35 to? The ones digit is 5, so we round 35 to 40.
Here's the simple rule: If the ones digit is 5 or more, round to the next tens number.
