Adding and subtracting fractions Two-step problems.
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Transcript of Adding and subtracting fractions Two-step problems.
![Page 1: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/1.jpg)
Adding and subtracting
fractions
Two-step problems
![Page 2: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/2.jpg)
What is a two-step problem?
Just how it sounds
![Page 3: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/3.jpg)
Two-step problem
• Solve the problem in the first step
• Solve the problem in the second step
• Now, you’re done
![Page 4: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/4.jpg)
Here’s an example
![Page 5: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/5.jpg)
Grandmother told the girls to gather wild rice from the lake shore
![Page 6: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/6.jpg)
The first granddaughter gathers rice from 4/7 of the shore
The second granddaughter gathers rice from 2/7 of the shore
How much of the shore is left?
![Page 7: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/7.jpg)
What is the first step?
Figure out how much wasalready gathered
![Page 8: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/8.jpg)
I gathered 4/7 of the rice
I gathered 4/7 of the rice
![Page 9: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/9.jpg)
I gathered 4/7 of the rice
I gathered 4/7 of the rice I gathered 2/7
of the rice I gathered 2/7
of the rice
![Page 10: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/10.jpg)
STEP ONE
4 + 2 = 6
7 7 7
This is how much rice was gathered already
![Page 11: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/11.jpg)
Step two
Subtract
Subtract from what?
Subtract from what?
![Page 12: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/12.jpg)
Step two
Subtract
Subtract from what?
Subtract from what?
Subtract from the whole
![Page 13: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/13.jpg)
This can be a tiny bit trickyYou have gathered rice from this fraction
6
7
You subtract from the whole. A whole of anything – a whole lake shore, a whole pot of stew, a whole snake, a whole anything is 1.
![Page 14: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/14.jpg)
1 - 6 = 7
7 - 6 = 1 7 7 7
![Page 15: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/15.jpg)
You could just count how
many pieces
You could just count how
many piecesand then see
how many pieces are left
and then seehow many
pieces are left
1 2 3 4 5 6 7
7 1
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That works IF you have a
model
That works IF you have a
model What if you don’t?
What if you don’t?
1 2 3 4 5 6 7
7 1
![Page 17: Adding and subtracting fractions Two-step problems.](https://reader035.fdocuments.net/reader035/viewer/2022062519/5697bfc31a28abf838ca56d6/html5/thumbnails/17.jpg)
If you don’t have a model
1. Add up the different fractions to find the total amount you have gathered
2. Subtract the answer you found in step one from 1
– Hint: You might find it easier to change 1 to a fraction like 7/7