Introduction
Remember how Mrs. Williams had to give out change in the last Concept? Well, she isn't finished yet. Take a look.
When Mrs. Williams got back to the bus, she found that the museum clerk had given her an additional 11 dollars in change. This 11 dollars would need to be distributed between the chaperones. Since 8 students went on the trip, Mrs. Williams would need to give some change to everyone.
"It's a good thing that she gave me a lot of change," Mrs. Williams thought to herself.
How much of the 11 dollars should each of the 8 chaperones receive?
You have been learning how to divide decimals. Now you are going to learn how to divide decimals when you need zero placeholders.
This Concept will teach you all that you need to know. Then you will be able to help Mrs. Williams divide up the money.
Guided Learning
In our last Concept, you learned to divide a decimal by a whole number. Remember here that the divisor is the whole number which goes outside of the division box and the dividend is the decimal that goes inside of the division box.
The problems in the last Concept were evenly divisible by their divisors . This means that at the end there wasn’t a remainder.
How do we divide decimals by whole numbers when there is a remainder ?
14.9 5 ______
The first thing that we can do is to set up this problem in a division box. The five is the divisor and the 14.9 is the dividend .
Next we start our division. Five goes into fourteen twice, with four left over. Then we bring down the 9. Five goes into 49, 9 times with four left over. Before you learned about decimals, that 4 would just be a remainder .
However, when we work with decimals, we don’t want to have a remainder . We can use a zero as a placeholder.
Here, we can add a zero to the dividend and then see if we can finish the division. We add a zero and combine that with the four so we have 40. Five divides into forty eight times. Here is what that would look like.
Our final answer is 2.98.
When working with decimals, you always want to add zeros as placeholders so that you can be sure that the decimal is as accurate as it can be. Remember that a decimal shows a part of a whole. We can make that part as specific as necessary.
Try a few of these on your own. Be sure to add zero placeholders as needed.
Example A
13.95 6 _____
Solution: _____
Example B
2.5 2 _____
Solution: _____
Example C
1.66 4 _____
Solution: ._____
Now that you know how to work with zero placeholders, let's go back to Mrs. Williams and the change. Here is the original problem once again.
When Mrs. Williams got back to the bus, she found that the museum clerk had given her an additional 11 dollars in change. This 11 dollars would need to be distributed between the chaperones. Since 8 chaperones went on the trip, Mrs. Williams would need to give some change to everyone.
"It's a good thing that she gave me a lot of change," Mrs. Williams thought to herself.
How much of the 11 dollars should each of the 8 chaperones receive?
To figure this out, we must first set up the math problem.
11 8 _____
Now we divide 11 by 8.
You can see that we had to add a decimal point and three zeros.
Each chaperone will receive $1.37 in change.
Here is one for you to try on your own.
Divide the following numbers.
Answer
To divide 3 by 8, we have to add a decimal point and a zero right away. Here is how we can rewrite the problem.
Now we can divide. We'll need to add two more zeros.
Our final answer is _________.
Video Review
Here are videos for review.
Khan Academy Dividing Decimals 2
Practice Set
Directions: Divide each decimal by each whole number. Add zero placeholders when necessary.
Review
- When we work with decimals, we don’t want to have a remainder . We can use a zero as a placeholder.
- When working with decimals, you always want to add zeros as placeholders.
- Remember that a decimal shows a part of a whole.
- We can make that part as specific as necessary.