math help

What is 2/10 + 1/4?

What is 2/10 + 1/4?

This is how we add

2
10
+
1
4

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 2 by 4, and get 8, then we multiply 10 by 4 and get 40.

2/10 times 4

Now for the second term. You multiply 1 by 10, and get 10, then multiply 10 by 4 and get 40.

1/4 times 10

This gives us a new problem that looks like so:

8
40
+
10
40

Step 2

Since our denominators match, we can add the numerators.

8 + 10 = 18

That gives us an answer of

18
40

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:

18
40
÷ 2 =
9
20

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 9. So we're done reducing.

And we're done! Here's the final answer to 2/10 + 1/4

2
10
+
1
4
=
9
20
© 2014 Randy Tayler