math help

What is 70/51 + 6/9?

What is 70/51 + 6/9?

This is how we add

70
51
+
6
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 70 by 9, and get 630, then we multiply 51 by 9 and get 459.

70/51 times 9

Do the same for the second term. We multiply 6 by 51, and get 306, then multiply 51 by 9 and get 459.

6/9 times 51

So now our fractions look like this:

630
459
+
306
459

Step 2

Since our denominators match, we can add the numerators.

630 + 306 = 936

So the answer is:

936
459

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. Try the next prime number, 3...

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

936
459
÷ 3 =
312
153

Now, try the same number again.

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

312
153
÷ 3 =
104
51

Now, try the same number again.

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...

No good. 53 is larger than 51. So we're done reducing.

Congratulations! Here's your final answer to 70/51 + 6/9

70
51
+
6
9
=
104
51
© 2014 Randy Tayler