math help

What is 11/12 + 7/8?

What is 11/12 + 7/8?

This is how we add

11
12
+
7
8

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 11 by 8, and get 88, then we multiply 12 by 8 and get 96.

11/12 times 8

Do the same for the second term. We multiply 7 by 12, and get 84, then multiply 12 by 8 and get 96.

7/8 times 12

The problem now has new fractions to add:

88
96
+
84
96

Step 2

Since our denominators match, we can add the numerators.

88 + 84 = 172

The sum we get is

172
96

Step 3

The last step is to reduce the fraction if we can.

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:

172
96
÷ 2 =
86
48

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:

86
48
÷ 2 =
43
24

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. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. 29 is larger than 24. So we're done reducing.

And we're done! Here's the final answer to 11/12 + 7/8

11
12
+
7
8
=
43
24
© 2014 Randy Tayler