math help

What is 78/10 + 4/11?

What is 78/10 + 4/11?

Here's how you add

78
10
+
4
11

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

78/10 times 11

Now for the second term. You multiply 4 by 10, and get 40, then multiply 10 by 11 and get 110.

4/11 times 10

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

858
110
+
40
110

Step 2

Since our denominators match, we can add the numerators.

858 + 40 = 898

That gives us the sum, which is

898
110

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:

898
110
÷ 2 =
449
55

Now, try the same number again.

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

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...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

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

Congratulations! Here's your final answer to 78/10 + 4/11

78
10
+
4
11
=
449
55
© 2014 Randy Tayler