math help

What is 21/33 + 1/9?

What is 21/33 + 1/9?

Let's add

21
33
+
1
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 21 by 9, and get 189, then we multiply 33 by 9 and get 297.

21/33 times 9

Do the same for the second term. We multiply 1 by 33, and get 33, then multiply 33 by 9 and get 297.

1/9 times 33

So now our fractions look like this:

189
297
+
33
297

Step 2

Since our denominators match, we can add the numerators.

189 + 33 = 222

So the answer is:

222
297

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:

222
297
÷ 3 =
74
99

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...

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

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

No good. 79 is larger than 74. So we're done reducing.

Congratulations! Here's your final answer to 21/33 + 1/9

21
33
+
1
9
=
74
99
© 2014 Randy Tayler