math help

What is 64/4 + 1/5?

What is 64/4 + 1/5?

Here's how we add

64
4
+
1
5

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 64 by 5, and get 320, then we multiply 4 by 5 and get 20.

64/4 times 5

Do the same for the second term. We multiply 1 by 4, and get 4, then multiply 4 by 5 and get 20.

1/5 times 4

The problem now has new fractions to add:

320
20
+
4
20

Step 2

Since our denominators match, we can add the numerators.

320 + 4 = 324

This yields the answer

324
20

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:

324
20
÷ 2 =
162
10

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:

162
10
÷ 2 =
81
5

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...

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

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 64/4 + 1/5

64
4
+
1
5
=
81
5
© 2014 Randy Tayler