math help

What is 5/100 + 3/12?

What is 5/100 + 3/12?

Let's add

5
100
+
3
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 3 by 100, and get 300, then multiply 100 by 12 and get 1200.

3/12 times 100

So now our fractions look like this:

60
1200
+
300
1200

Step 2

Since our denominators match, we can add the numerators.

60 + 300 = 360

So the answer is:

360
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:

360
1200
÷ 2 =
180
600

Let's try dividing by that again...

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

180
600
÷ 2 =
90
300

Let's try dividing by that again...

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

90
300
÷ 2 =
45
150

Let's try dividing by that again...

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:

45
150
÷ 3 =
15
50

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:

15
50
÷ 5 =
3
10

Let's try dividing by that again...

No good. 5 is larger than 3. So we're done reducing.

There you have it! Here's the final answer to 5/100 + 3/12

5
100
+
3
12
=
3
10
© 2014 Randy Tayler