math help

What is 5/100 + 5/12?

What is 5/100 + 5/12?

This is how we add

5
100
+
5
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 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 5 by 100, and get 500, then multiply 100 by 12 and get 1200.

5/12 times 100

The problem now has new fractions to add:

60
1200
+
500
1200

Step 2

Since our denominators match, we can add the numerators.

60 + 500 = 560

This yields the answer

560
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:

560
1200
÷ 2 =
280
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:

280
600
÷ 2 =
140
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:

140
300
÷ 2 =
70
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:

70
150
÷ 2 =
35
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...

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

35
75
÷ 5 =
7
15

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 7...

No good. So next you try the next prime number, which is 11...

No good. 11 is larger than 7. So we're done reducing.

And we're done! Here's the final answer to 5/100 + 5/12

5
100
+
5
12
=
7
15
© 2014 Randy Tayler