math help

What is 7/16 + 8/10?

What is 7/16 + 8/10?

This is how to add

7
16
+
8
10

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 7 by 10, and get 70, then we multiply 16 by 10 and get 160.

7/16 times 10

Now for the second term. You multiply 8 by 16, and get 128, then multiply 16 by 10 and get 160.

8/10 times 16

This gives us a new problem that looks like so:

70
160
+
128
160

Step 2

Since our denominators match, we can add the numerators.

70 + 128 = 198

That gives us an answer of

198
160

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

198
160
÷ 2 =
99
80

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. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. So next you try the next prime number, which is 83...

No good. 83 is larger than 80. So we're done reducing.

And we're done! Here's the final answer to 7/16 + 8/10

7
16
+
8
10
=
99
80
© 2014 Randy Tayler