math help

What is 20/64 + 7/12?

What is 20/64 + 7/12?

Here's how you add

20
64
+
7
12

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 20 by 12, and get 240, then we multiply 64 by 12 and get 768.

20/64 times 12

Now for the second term. You multiply 7 by 64, and get 448, then multiply 64 by 12 and get 768.

7/12 times 64

We now have a new problem, that looks like this:

240
768
+
448
768

Step 2

Since our denominators match, we can add the numerators.

240 + 448 = 688

That gives us the sum, which is

688
768

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

688
768
÷ 2 =
344
384

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

344
384
÷ 2 =
172
192

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

172
192
÷ 2 =
86
96

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

86
96
÷ 2 =
43
48

Now, try the same number again.

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

No good. 47 is larger than 43. So we're done reducing.

Congratulations! Here's your final answer to 20/64 + 7/12

20
64
+
7
12
=
43
48
© 2014 Randy Tayler