math help

What is 80/2 + 8/11?

What is 80/2 + 8/11?

This is how we add

80
2
+
8
11

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 80 by 11, and get 880, then we multiply 2 by 11 and get 22.

80/2 times 11

Now for the second term. You multiply 8 by 2, and get 16, then multiply 2 by 11 and get 22.

8/11 times 2

This gives us a new problem that looks like so:

880
22
+
16
22

Step 2

Since our denominators match, we can add the numerators.

880 + 16 = 896

So what's the answer so far?

896
22

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:

896
22
÷ 2 =
448
11

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. 13 is larger than 11. So we're done reducing.

And we're done! Here's the final answer to 80/2 + 8/11

80
2
+
8
11
=
448
11
© 2014 Randy Tayler