math help

What is 5/100 + 7/12?

What is 5/100 + 7/12?

Here's how you add

5
100
+
7
12

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 5 by 12, and get 60, then we multiply 100 by 12 and get 1200.

5/100 times 12

Do the same for the second term. We multiply 7 by 100, and get 700, then multiply 100 by 12 and get 1200.

7/12 times 100

So now our fractions look like this:

60
1200
+
700
1200

Step 2

Since our denominators match, we can add the numerators.

60 + 700 = 760

Now we have an answer.

760
1200

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:

760
1200
÷ 2 =
380
600

Now, try the same number again.

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

380
600
÷ 2 =
190
300

Now, try the same number again.

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

190
300
÷ 2 =
95
150

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:

95
150
÷ 5 =
19
30

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...

No good. 23 is larger than 19. So we're done reducing.

Congratulations! Here's your final answer to 5/100 + 7/12

5
100
+
7
12
=
19
30
© 2014 Randy Tayler