math help

What is 80/2 + 6/7?

What is 80/2 + 6/7?

Here's how we add

80
2
+
6
7

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 80 by 7, and get 560, then we multiply 2 by 7 and get 14.

80/2 times 7

Now for the second term. You multiply 6 by 2, and get 12, then multiply 2 by 7 and get 14.

6/7 times 2

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

560
14
+
12
14

Step 2

Since our denominators match, we can add the numerators.

560 + 12 = 572

That gives us the sum, which is

572
14

Step 3

Now, do we need to simplify this fraction?

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

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

572
14
÷ 2 =
286
7

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. 11 is larger than 7. So we're done reducing.

And we're done! Here's the final answer to 80/2 + 6/7

80
2
+
6
7
=
286
7
© 2014 Randy Tayler