math help

What is 91/6 + 2/9?

What is 91/6 + 2/9?

This is how we add

91
6
+
2
9

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 91 by 9, and get 819, then we multiply 6 by 9 and get 54.

91/6 times 9

Do the same for the second term. We multiply 2 by 6, and get 12, then multiply 6 by 9 and get 54.

2/9 times 6

So now our fractions look like this:

819
54
+
12
54

Step 2

Since our denominators match, we can add the numerators.

819 + 12 = 831

Now we have an answer.

831
54

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...

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

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

831
54
÷ 3 =
277
18

Let's try dividing by that again...

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...

No good. 19 is larger than 18. So we're done reducing.

There you have it! Here's the final answer to 91/6 + 2/9

91
6
+
2
9
=
277
18
© 2014 Randy Tayler