math help

What is 21/33 + 5/10?

What is 21/33 + 5/10?

This is how to add

21
33
+
5
10

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 21 by 10, and get 210, then we multiply 33 by 10 and get 330.

21/33 times 10

Now for the second term. You multiply 5 by 33, and get 165, then multiply 33 by 10 and get 330.

5/10 times 33

This gives us a new problem that looks like so:

210
330
+
165
330

Step 2

Since our denominators match, we can add the numerators.

210 + 165 = 375

So what's the answer so far?

375
330

Step 3

Can this fraction be reduced?

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

Nope! So now we try the next greatest prime number, 3...

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

375
330
÷ 3 =
125
110

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

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

125
110
÷ 5 =
25
22

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

No good. 23 is larger than 22. So we're done reducing.

There you have it! Here's the final answer to 21/33 + 5/10

21
33
+
5
10
=
25
22
© 2014 Randy Tayler