math help

What is 3/18 + 9/10?

What is 3/18 + 9/10?

Here's how you add

3
18
+
9
10

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

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

3/18 times 10

Do the same for the second term. We multiply 9 by 18, and get 162, then multiply 18 by 10 and get 180.

9/10 times 18

So now our fractions look like this:

30
180
+
162
180

Step 2

Since our denominators match, we can add the numerators.

30 + 162 = 192

So the answer is:

192
180

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

192
180
÷ 2 =
96
90

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

96
90
÷ 2 =
48
45

Now, try the same number again.

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

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

48
45
÷ 3 =
16
15

Now, try the same number again.

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

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

No good. 17 is larger than 16. So we're done reducing.

Congratulations! Here's your final answer to 3/18 + 9/10

3
18
+
9
10
=
16
15
© 2014 Randy Tayler