math help

What is 5/8 + 2/7?

What is 5/8 + 2/7?

Let's add

5
8
+
2
7

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 5 by 7, and get 35, then we multiply 8 by 7 and get 56.

5/8 times 7

Do the same for the second term. We multiply 2 by 8, and get 16, then multiply 8 by 7 and get 56.

2/7 times 8

The problem now has new fractions to add:

35
56
+
16
56

Step 2

Since our denominators match, we can add the numerators.

35 + 16 = 51

The sum we get is

51
56

Step 3

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

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

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...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

No good. 53 is larger than 51. So we're done reducing.

Congratulations! Here's your final answer to 5/8 + 2/7

5
8
+
2
7
=
51
56
© 2014 Randy Tayler