Question

Multiplying Mixed numbers! Please help! 4 1/3 times 2 1/4? I got 29 1/4 as the answer when the correct answer is suppose to be 9 3/4 or 39/4.

Answer 1

So I first convert the mixed numbers to improper fractions and I get 13/1 and 9/4 so I then multiply and get 117/4 which then equals 29 1/4 as my answer. What am I doing wrong?

Answer 2

Just great that you have remembered and used material from previous problems!!

Check your first "improper fraction;" you have an arithmetic mistake there.

Answer 3

Convert 2 1/4 to an improper fraction.

Answer 4

2 times 4 is 8 plus 1 equals 9/4?

Answer 5

Did I covert it wrong?

Answer 6

that's better.

What are your 2 improper fractions?

Show the product of these 2 improper fractions.

Answer 7

13/1 times 9/4 equals 117/4

Answer 8

Like this: (fraction 1) * (fraction 2)

Answer 9

13/1 * 9/4 equals 117/4

Answer 10

But one of the mixed numbers is 4 1/3. What happened to the denominator, 3?

Answer 11

\[\frac{ 13 }{ ? }*\frac{ 9 }{ 4 }=?\]

Answer 12

But we turned that into a improper fraction so the denominator became 1...

Answer 13

13/1

Answer 14

Not so.

Answer 15

Try again.

Answer 16

Umm is there something I need to do after converting them to improper fractions to make them have the same denominator?

Answer 17

Here's what we do with 4 1/3:
1. Multiply that 4 by 3.
2. Add 1 to your result.
3. Write this latest result as the numerator of a fraction with 3 in the denom.

Answer 18

One question at a time.
Please convert 4 1/3 to an improper fraction.

Answer 19

Ohhh okay I see what I did wrong with that

Answer 20

What are the 2 improper fractions that you're multiplying?

Answer 21

13/3 and 9/4

Answer 22

13/3 *9/4 = 117/12 right?

Answer 23

Right. 13/3 is correct/ 13/1 is not.

Now write the product of 13/3 and 9/4.

Answer 24

117/12 but that has to be simplified right?

Answer 25

Try this: \[\frac{ 13 }{ 3 }*\frac{ 9 }{ 4 }\]

Answer 26

Instead of multiplying 13 by 9, CANCEL the 9 and the 3. Be careful.

Answer 27

Wait, cancel the 9 and 3?

Answer 28

3*3/3 = ?

Answer 29

Dont we just multiply 13 times 9 and 3 times 4

Answer 30

3

Answer 31

\[\frac{ 3(3) }{ 3 }=?\]

Answer 32

9/3=3

Answer 33

What is your final result?

13/3 times 9/4

Answer 34

39/4

Answer 35

That's it. So much easier to cancel instead of multiplying.

Answer 36

Thanks so much for helping me find my error!

Answer 37

My pleasure. Keep up the good work and the good attitude.

Answer 38

Thank you! Have a great evening!