math help

What is 30/50 + 4/12?

What is 30/50 + 4/12?

Here's how you add

30
50
+
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 30 by 12, and get 360, then we multiply 50 by 12 and get 600.

30/50 times 12

Do the same for the second term. We multiply 4 by 50, and get 200, then multiply 50 by 12 and get 600.

4/12 times 50

So now our fractions look like this:

360
600
+
200
600

Step 2

Since our denominators match, we can add the numerators.

360 + 200 = 560

So the answer is:

560
600

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:

560
600
÷ 2 =
280
300

Let's try dividing by that again...

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

280
300
÷ 2 =
140
150

Let's try dividing by that again...

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

140
150
÷ 2 =
70
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:

70
75
÷ 5 =
14
15

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

No good. 17 is larger than 14. So we're done reducing.

There you have it! Here's the final answer to 30/50 + 4/12

30
50
+
4
12
=
14
15
© 2014 Randy Tayler