math help

What is 80/2 + 1/5?

What is 80/2 + 1/5?

Here's how we add

80
2
+
1
5

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 80 by 5, and get 400, then we multiply 2 by 5 and get 10.

80/2 times 5

Do the same for the second term. We multiply 1 by 2, and get 2, then multiply 2 by 5 and get 10.

1/5 times 2

So now our fractions look like this:

400
10
+
2
10

Step 2

Since our denominators match, we can add the numerators.

400 + 2 = 402

So the answer is:

402
10

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:

402
10
÷ 2 =
201
5

Now, try the same number again.

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

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

Congratulations! Here's your final answer to 80/2 + 1/5

80
2
+
1
5
=
201
5
© 2014 Randy Tayler