math help

What is 100/100 + 4/12?

What is 100/100 + 4/12?

This is how to add

100
100
+
4
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 100 by 12, and get 1200, then we multiply 100 by 12 and get 1200.

100/100 times 12

Do the same for the second term. We multiply 4 by 100, and get 400, then multiply 100 by 12 and get 1200.

4/12 times 100

So now our fractions look like this:

1200
1200
+
400
1200

Step 2

Since our denominators match, we can add the numerators.

1200 + 400 = 1600

So the answer is:

1600
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:

1600
1200
÷ 2 =
800
600

Let's try dividing by that again...

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

800
600
÷ 2 =
400
300

Let's try dividing by that again...

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

400
300
÷ 2 =
200
150

Let's try dividing by that again...

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

200
150
÷ 2 =
100
75

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

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:

100
75
÷ 5 =
20
15

Let's try dividing by that again...

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

20
15
÷ 5 =
4
3

Let's try dividing by that again...

No good. 5 is larger than 4. So we're done reducing.

There you have it! Here's the final answer to 100/100 + 4/12

100
100
+
4
12
=
4
3
© 2014 Randy Tayler