math help

What is 80/2 + 4/7?

What is 80/2 + 4/7?

This is how you add

80
2
+
4
7

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

80/2 times 7

Now for the second term. You multiply 4 by 2, and get 8, then multiply 2 by 7 and get 14.

4/7 times 2

This gives us a new problem that looks like so:

560
14
+
8
14

Step 2

Since our denominators match, we can add the numerators.

560 + 8 = 568

So what's the answer so far?

568
14

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:

568
14
÷ 2 =
284
7

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

No good. 11 is larger than 7. So we're done reducing.

There you have it! Here's the final answer to 80/2 + 4/7

80
2
+
4
7
=
284
7
© 2014 Randy Tayler