math help

What is 7/20 + 4/10?

What is 7/20 + 4/10?

This is how to add

7
20
+
4
10

Step 1

We have to make sure the denominators are equal.

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

Multiply 4 by 2, and get 8, then we multiply 10 by 2 and get 20.

4/10 times 2

This gives us a new problem that looks like so:

7
20
+
8
20

Step 2

Since our denominators match, we can add the numerators.

7 + 8 = 15

That gives us an answer of

15
20

Step 3

Can this fraction be reduced?

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

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...

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

15
20
÷ 5 =
3
4

So far so good... let's try to divide by that number again.

No good. 5 is larger than 3. So we're done reducing.

And we're done! Here's the final answer to 7/20 + 4/10

7
20
+
4
10
=
3
4
© 2014 Randy Tayler