math help

What is 78/10 + 1/12?

What is 78/10 + 1/12?

This is how we add

78
10
+
1
12

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 78 by 12, and get 936, then we multiply 10 by 12 and get 120.

78/10 times 12

Now for the second term. You multiply 1 by 10, and get 10, then multiply 10 by 12 and get 120.

1/12 times 10

This gives us a new problem that looks like so:

936
120
+
10
120

Step 2

Since our denominators match, we can add the numerators.

936 + 10 = 946

So what's the answer so far?

946
120

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

946
120
÷ 2 =
473
60

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. So next you try the next prime number, which is 61...

No good. 61 is larger than 60. So we're done reducing.

And we're done! Here's the final answer to 78/10 + 1/12

78
10
+
1
12
=
473
60
© 2014 Randy Tayler