math help

What is 30/50 + 9/11?

What is 30/50 + 9/11?

This is how you add

30
50
+
9
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 30 by 11, and get 330, then we multiply 50 by 11 and get 550.

30/50 times 11

Do the same for the second term. We multiply 9 by 50, and get 450, then multiply 50 by 11 and get 550.

9/11 times 50

So now our fractions look like this:

330
550
+
450
550

Step 2

Since our denominators match, we can add the numerators.

330 + 450 = 780

Now we have an answer.

780
550

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:

780
550
÷ 2 =
390
275

Now, try the same number again.

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

Nope. Try the next prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

390
275
÷ 5 =
78
55

Now, try the same number again.

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 30/50 + 9/11

30
50
+
9
11
=
78
55
© 2014 Randy Tayler