math help

What is 21/11 + 6/12?

What is 21/11 + 6/12?

Let's add

21
11
 +
6
12

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 21 by 12, and get 252, then we multiply 11 by 12 and get 132.

21/11 times 12

Do the same for the second term. We multiply 6 by 11, and get 66, then multiply 11 by 12 and get 132.

6/12 times 11

The problem now has new fractions to add:

252
132
 +
66
132

Step 2

Since our denominators match, we can add the numerators.

252 + 66 = 318

This yields the answer

318
132

Step 3

The last step is to reduce the fraction if we can.

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:

318
132
 ÷ 2 =
159
66

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...

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

159
66
 ÷ 3 =
53
22

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 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. 23 is larger than 22. So we're done reducing.

And we're done! Here's the final answer to 21/11 + 6/12

21
11
 +
6
12
 =
53
22
© 2014 Randy Tayler

6/12 + 1/2
6/12 - 1/2
6/12 + 1/3
6/12 - 1/3
6/12 + 2/3
6/12 - 2/3
6/12 + 1/4
6/12 - 1/4
6/12 + 2/4
6/12 - 2/4
6/12 + 3/4
6/12 - 3/4
6/12 + 1/5
6/12 - 1/5
6/12 + 2/5
6/12 - 2/5
6/12 + 3/5
6/12 - 3/5
6/12 + 4/5
6/12 - 4/5
6/12 + 1/6
6/12 - 1/6
6/12 + 2/6
6/12 - 2/6
6/12 + 3/6
6/12 - 3/6
6/12 + 4/6
6/12 - 4/6
6/12 + 5/6
6/12 - 5/6
6/12 + 1/7
6/12 - 1/7
6/12 + 2/7
6/12 - 2/7
6/12 + 3/7
6/12 - 3/7
6/12 + 4/7
6/12 - 4/7
6/12 + 5/7
6/12 - 5/7
6/12 + 6/7
6/12 - 6/7
6/12 + 1/8
6/12 - 1/8
6/12 + 2/8
6/12 - 2/8
6/12 + 3/8
6/12 - 3/8
6/12 + 4/8
6/12 - 4/8
6/12 + 5/8
6/12 - 5/8
6/12 + 6/8
6/12 - 6/8
6/12 + 7/8
6/12 - 7/8
6/12 + 1/9
6/12 - 1/9
6/12 + 2/9
6/12 - 2/9
6/12 + 3/9
6/12 - 3/9
6/12 + 4/9
6/12 - 4/9
6/12 + 5/9
6/12 - 5/9
6/12 + 6/9
6/12 - 6/9
6/12 + 7/9
6/12 - 7/9
6/12 + 8/9
6/12 - 8/9
6/12 + 1/10
6/12 - 1/10
6/12 + 2/10
6/12 - 2/10
6/12 + 3/10
6/12 - 3/10
6/12 + 4/10
6/12 - 4/10
6/12 + 5/10
6/12 - 5/10
6/12 + 6/10
6/12 - 6/10
6/12 + 7/10
6/12 - 7/10
6/12 + 8/10
6/12 - 8/10
6/12 + 9/10
6/12 - 9/10
6/12 + 1/11
6/12 - 1/11
6/12 + 2/11
6/12 - 2/11
6/12 + 3/11
6/12 - 3/11
6/12 + 4/11
6/12 - 4/11
6/12 + 5/11
6/12 - 5/11
6/12 + 6/11
6/12 - 6/11
6/12 + 7/11
6/12 - 7/11
6/12 + 8/11
6/12 - 8/11
6/12 + 9/11
6/12 - 9/11
6/12 + 10/11
6/12 - 10/11
6/12 + 1/12
6/12 - 1/12
6/12 + 2/12
6/12 - 2/12
6/12 + 3/12
6/12 - 3/12
6/12 + 4/12
6/12 - 4/12
6/12 + 5/12
6/12 - 5/12
6/12 + 6/12
6/12 - 6/12
6/12 + 7/12
6/12 - 7/12
6/12 + 8/12
6/12 - 8/12
6/12 + 9/12
6/12 - 9/12
6/12 + 10/12
6/12 - 10/12
6/12 + 11/12
6/12 - 11/12