math help

What is 25/15 + 6/8?

What is 25/15 + 6/8?

Here's how you add

25
15
+
6
8

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 25 by 8, and get 200, then we multiply 15 by 8 and get 120.

25/15 times 8

Do the same for the second term. We multiply 6 by 15, and get 90, then multiply 15 by 8 and get 120.

6/8 times 15

The problem now has new fractions to add:

200
120
+
90
120

Step 2

Since our denominators match, we can add the numerators.

200 + 90 = 290

The sum we get is

290
120

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:

290
120
÷ 2 =
145
60

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:

145
60
÷ 5 =
29
12

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...

No good. 13 is larger than 12. So we're done reducing.

There you have it! Here's the final answer to 25/15 + 6/8

25
15
+
6
8
=
29
12
© 2014 Randy Tayler