math help

What is 78/10 + 5/11?

What is 78/10 + 5/11?

This is how to add

78
10
+
5
11

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 78 by 11, and get 858, then we multiply 10 by 11 and get 110.

78/10 times 11

Do the same for the second term. We multiply 5 by 10, and get 50, then multiply 10 by 11 and get 110.

5/11 times 10

So now our fractions look like this:

858
110
+
50
110

Step 2

Since our denominators match, we can add the numerators.

858 + 50 = 908

So the answer is:

908
110

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:

908
110
÷ 2 =
454
55

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. 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. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. 59 is larger than 55. So we're done reducing.

And we're done! Here's the final answer to 78/10 + 5/11

78
10
+
5
11
=
454
55
© 2014 Randy Tayler