math help

What is 3/18 + 4/10?

What is 3/18 + 4/10?

Here's how to add

3
18
+
4
10

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 3 by 10, and get 30, then we multiply 18 by 10 and get 180.

3/18 times 10

Now for the second term. You multiply 4 by 18, and get 72, then multiply 18 by 10 and get 180.

4/10 times 18

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

30
180
+
72
180

Step 2

Since our denominators match, we can add the numerators.

30 + 72 = 102

Answer:

102
180

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:

102
180
÷ 2 =
51
90

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...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

51
90
÷ 3 =
17
30

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 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. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. 19 is larger than 17. So we're done reducing.

And we're done! Here's the final answer to 3/18 + 4/10

3
18
+
4
10
=
17
30
© 2014 Randy Tayler