This activity will test how well you have learned rounding decimal numbers. You will need a clean sheet of paper, a pencil, several different colored crayons, and a ruler.
Copy this table onto your paper.
|
4.16 |
7.75 |
6.17 |
5.352 |
|
5.619 |
6.42 |
4.27 |
7.9 |
|
7.84 |
5.43 |
7.845 |
6.347 |
|
4.3 |
6.22 |
5.7 |
4.189 |
The rules are very simple. Using what you've learned about rounding decimal numbers, find the numbers that round the same way. Show this by using matching colors to color in the numbers that match. Here is an example:
|
2.545 |
2.27 |
2.37 |
|
2.4 |
2.31 |
2.6 |
Notice that there are three different colors for three different pairs of matching numbers. Those are the matched numbers. But how did we get those answers?
Remember the rule? Round up when the digit beside the decimal number you want to round off is 5 or greater (larger) than 5. Let's see if the paired numbers are correct.
Let's check the paired numbers in blue. Is 2.545 approximately equal to 2.6?
First, we round off to the nearest hundredths. Underline the hundredths number:
2.545
Our hundredths number is 4. The digit beside 4 is the thousandths number, which is 5:
2.545
Following the rule, we round up our hundredths number, and our number becomes 2.55. Now round our new number to the nearest tenths. Underline the tenths number:
2.55
Our tenths number is 5. The digit beside 5 is the new hundredths number, which is 5:
2.55
We round up our tenths number, and we get 2.6. So are our numbers approximately equal? Yes, they are. The other two pairs are also approximately equal.
Now it's your turn. Round up and match up!
Ready to move on to the next lesson?
Rounding Decimals Basics
