Question

Hi, I need help adding and subtracting fractions. 1/2+3/4+5/8=

Answer 1

When adding and subtracting fractions you want to get a common denominatour. Do you know how to do that?

Answer 2

no

Answer 3

It is called the least common denominatour. Basically what it is, is you want the same number on bottom on all of the fractions. To get this, you must find the smalles number that all the fractions can multiply into.

Answer 4

For this problem, all three fractions can multiply into 8

Answer 5

okay

Answer 6

And what you do to the bottom of a fraction, you must do to the top. What multiplies by 2 to get 8?

Answer 7

4

Answer 8

So for the fraction 1/2 you must multiply both the one and two by 4. What does the fraction become?

Answer 9

4/8

Answer 10

perfect! Do you have any idea what to do to the 3/4?

Answer 11

not sure 12/16

Answer 12

remember. you are shooting for an 8 as the denominatour. so what do you multiply 4 by to get eight?

Answer 13

6/8

Answer 14

yes! Now that you have all of the denominatours the same, all you have to do is add the top numbers and keep the 8 the same. try that

Answer 15

4/8+6/8+5/8

Answer 16

15/8

Answer 17

that is right! Do you want to try one more problem like this?

Answer 18

Thank you, yes please

Answer 19

okay try this:
2/4+7/16+3/8
Do you know what number the bottom will be? (remember, you want a number where all the bottom number will be the same)

Answer 20

16

Answer 21

yes, so can you figure out what to multiply everything by so all the bottom numbers are 16? (remember, what you do to the bottom, you must do to the top)

Answer 22

I do not remember sorry

Answer 23

you have 2/4, 7/16, and 3/8
7/16 doesn't change. but what do you multiply four by to get 16?

Answer 24

4

Answer 25

so multiply both the bottom and top by four

Answer 26

14/28

Answer 27

Are you sure? Try again

Answer 28

12/64

Answer 29

What is 4 times 4? remember, we are working with fraction 2/4 right now

Answer 30

16

Answer 31

2/4

Answer 32

so we multiply 4x4 to get 16.
But what we do to the bottom.. We must do to the top. So you multiply 2x4

Answer 33

do you have the answer?

Answer 34

sorry my computer froze

Answer 35

8/16

Answer 36

yes. So now we have 8/16, 7/16, and 3/8.
What do you think we do to the last fraction to make it like the other two?

Answer 37

multiply 3*8 which is 24/16

Answer 38

Not exactly. remember, the goal is to get ALL the bottom numbers 16. What time 8 is 16?

Answer 39

2

Answer 40

yes, so you multiply both the bottom and top by 2. What do you get?

Answer 41

3/16

Answer 42

what you do to the bottom, you must do to the top. What is your new fraction?

Answer 43

3/32

Answer 44

Thanks for you help I have to get off the computer now.

Answer 45

Your bottom number was right when it was 16. your top one isn't right. you multiplied 8*2 to get sixteen, so you MUST MUST MUST multiply your top number by 2

Answer 46

ok. good bye

Answer 47

okay, thank you so much for all your time

Answer 48

No problem! I hope you figure this stuff out :-)