math help

What is 20/64 + 9/10?

What is 20/64 + 9/10?

Here's how you add

20
64
+
9
10

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 10, and get 200, then we multiply 64 by 10 and get 640.

20/64 times 10

Now for the second term. You multiply 9 by 64, and get 576, then multiply 64 by 10 and get 640.

9/10 times 64

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

200
640
+
576
640

Step 2

Since our denominators match, we can add the numerators.

200 + 576 = 776

That gives us the sum, which is

776
640

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:

776
640
÷ 2 =
388
320

Now, try the same number again.

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

388
320
÷ 2 =
194
160

Now, try the same number again.

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

194
160
÷ 2 =
97
80

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...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

No good. 83 is larger than 80. So we're done reducing.

Congratulations! Here's your final answer to 20/64 + 9/10

20
64
+
9
10
=
97
80
© 2014 Randy Tayler