math help

What is 15/11 + 2/8?

What is 15/11 + 2/8?

Let's add

15
11
+
2
8

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 15 by 8, and get 120, then we multiply 11 by 8 and get 88.

15/11 times 8

Do the same for the second term. We multiply 2 by 11, and get 22, then multiply 11 by 8 and get 88.

2/8 times 11

So now our fractions look like this:

120
88
+
22
88

Step 2

Since our denominators match, we can add the numerators.

120 + 22 = 142

Now we have an answer.

142
88

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:

142
88
÷ 2 =
71
44

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

No good. 47 is larger than 44. So we're done reducing.

There you have it! Here's the final answer to 15/11 + 2/8

15
11
+
2
8
=
71
44
© 2014 Randy Tayler