math help

What is 9/100 + 1/12?

What is 9/100 + 1/12?

This is how we add

9
100
+
1
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 9 by 12, and get 108, then we multiply 100 by 12 and get 1200.

9/100 times 12

Do the same for the second term. We multiply 1 by 100, and get 100, then multiply 100 by 12 and get 1200.

1/12 times 100

The problem now has new fractions to add:

108
1200
+
100
1200

Step 2

Since our denominators match, we can add the numerators.

108 + 100 = 208

This yields the answer

208
1200

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:

208
1200
÷ 2 =
104
600

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

104
600
÷ 2 =
52
300

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

52
300
÷ 2 =
26
150

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

26
150
÷ 2 =
13
75

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...

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. 17 is larger than 13. So we're done reducing.

And we're done! Here's the final answer to 9/100 + 1/12

9
100
+
1
12
=
13
75
© 2014 Randy Tayler