math help

What is 53/9 + 4/12?

What is 53/9 + 4/12?

Let's add

53
9
+
4
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 53 by 12, and get 636, then we multiply 9 by 12 and get 108.

53/9 times 12

Do the same for the second term. We multiply 4 by 9, and get 36, then multiply 9 by 12 and get 108.

4/12 times 9

The problem now has new fractions to add:

636
108
+
36
108

Step 2

Since our denominators match, we can add the numerators.

636 + 36 = 672

The sum we get is

672
108

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:

672
108
÷ 2 =
336
54

Let's try dividing by that again...

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

336
54
÷ 2 =
168
27

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:

168
27
÷ 3 =
56
9

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

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

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

No good. 11 is larger than 9. So we're done reducing.

There you have it! Here's the final answer to 53/9 + 4/12

53
9
+
4
12
=
56
9
© 2014 Randy Tayler