math help

What is 64/16 + 4/5?

What is 64/16 + 4/5?

Here's how you add

64
16
+
4
5

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 64 by 5, and get 320, then we multiply 16 by 5 and get 80.

64/16 times 5

Now for the second term. You multiply 4 by 16, and get 64, then multiply 16 by 5 and get 80.

4/5 times 16

This gives us a new problem that looks like so:

320
80
+
64
80

Step 2

Since our denominators match, we can add the numerators.

320 + 64 = 384

That gives us an answer of

384
80

Step 3

Can this fraction be reduced?

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

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

384
80
÷ 2 =
192
40

So far so good... let's try to divide by that number again.

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

192
40
÷ 2 =
96
20

So far so good... let's try to divide by that number again.

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

96
20
÷ 2 =
48
10

So far so good... let's try to divide by that number again.

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

48
10
÷ 2 =
24
5

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. 7 is larger than 5. So we're done reducing.

And we're done! Here's the final answer to 64/16 + 4/5

64
16
+
4
5
=
24
5
© 2014 Randy Tayler