What is 15/60 + 3/8?

This is how you add

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 15 by 8, and get 120, then we multiply 60 by 8 and get 480.

Do the same for the second term. We multiply 3 by 60, and get 180, then multiply 60 by 8 and get 480.

The problem now has new fractions to add:

Step 2

Since our denominators match, we can add the numerators.

120 + 180 = 300

The sum we get is

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:

So far so good... let's try to divide by that number again.

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

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

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

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 7...

No good. 7 is larger than 5. So we're done reducing.

And we're done! Here's the final answer to 15/60 + 3/8