math help

What is 80/2 + 5/10?

What is 80/2 + 5/10?

This is how to add

80
2
+
5
10

Step 1

Our denominators (bottom numbers) don't match, so we can't add yet.

10 goes into 2 evenly, so we only need to multiply one term to get a common denominator.

Multiply 80 by 5, and get 400, then we multiply 2 by 5 and get 10.

80/2 times 5

This gives us a new problem that looks like so:

400
10
+
5
10

Step 2

Since our denominators match, we can add the numerators.

400 + 5 = 405

That gives us an answer of

405
10

Step 3

Can this fraction be reduced?

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

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

405
10
÷ 5 =
81
2

Now, try the same number again.

No good. 5 is larger than 2. So we're done reducing.

Congratulations! Here's your final answer to 80/2 + 5/10

80
2
+
5
10
=
81
2
© 2014 Randy Tayler