math help

What is 5/7 + 9/10?

What is 5/7 + 9/10?

This is how we add

5
7
+
9
10

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 5 by 10, and get 50, then we multiply 7 by 10 and get 70.

5/7 times 10

Now for the second term. You multiply 9 by 7, and get 63, then multiply 7 by 10 and get 70.

9/10 times 7

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

50
70
+
63
70

Step 2

Since our denominators match, we can add the numerators.

50 + 63 = 113

That gives us the sum, which is

113
70

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide 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...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

No good. 71 is larger than 70. So we're done reducing.

Congratulations! Here's your final answer to 5/7 + 9/10

5
7
+
9
10
=
113
70
© 2014 Randy Tayler