math help

What is 31/12 + 4/8?

What is 31/12 + 4/8?

This is how to add

31
12
+
4
8

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 31 by 8, and get 248, then we multiply 12 by 8 and get 96.

31/12 times 8

Now for the second term. You multiply 4 by 12, and get 48, then multiply 12 by 8 and get 96.

4/8 times 12

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

248
96
+
48
96

Step 2

Since our denominators match, we can add the numerators.

248 + 48 = 296

That gives us the sum, which is

296
96

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:

296
96
÷ 2 =
148
48

Now, try the same number again.

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

148
48
÷ 2 =
74
24

Now, try the same number again.

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

74
24
÷ 2 =
37
12

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...

No good. 13 is larger than 12. So we're done reducing.

Congratulations! Here's your final answer to 31/12 + 4/8

31
12
+
4
8
=
37
12
© 2014 Randy Tayler