math help

What is 20/64 + 4/12?

What is 20/64 + 4/12?

This is how you add

20
64
+
4
12

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

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

20/64 times 12

Do the same for the second term. We multiply 4 by 64, and get 256, then multiply 64 by 12 and get 768.

4/12 times 64

So now our fractions look like this:

240
768
+
256
768

Step 2

Since our denominators match, we can add the numerators.

240 + 256 = 496

Now we have an answer.

496
768

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

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

496
768
÷ 2 =
248
384

Now, try the same number again.

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

248
384
÷ 2 =
124
192

Now, try the same number again.

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

124
192
÷ 2 =
62
96

Now, try the same number again.

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

62
96
÷ 2 =
31
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...

No good. 37 is larger than 31. So we're done reducing.

Congratulations! Here's your final answer to 20/64 + 4/12

20
64
+
4
12
=
31
48
© 2014 Randy Tayler