math help

What is 7/12 + 7/8?

What is 7/12 + 7/8?

This is how to add

7
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 7 by 8, and get 56, then we multiply 12 by 8 and get 96.

7/12 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:

56
96
+
84
96

Step 2

Since our denominators match, we can add the numerators.

56 + 84 = 140

This yields the answer

140
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:

140
96
÷ 2 =
70
48

Now, try the same number again.

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

70
48
÷ 2 =
35
24

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...

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

Congratulations! Here's your final answer to 7/12 + 7/8

7
12
+
7
8
=
35
24
© 2014 Randy Tayler