math help

What is 80/2 + 1/7?

What is 80/2 + 1/7?

This is how to add

80
2
+
1
7

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 80 by 7, and get 560, then we multiply 2 by 7 and get 14.

80/2 times 7

Do the same for the second term. We multiply 1 by 2, and get 2, then multiply 2 by 7 and get 14.

1/7 times 2

The problem now has new fractions to add:

560
14
+
2
14

Step 2

Since our denominators match, we can add the numerators.

560 + 2 = 562

This yields the answer

562
14

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:

562
14
÷ 2 =
281
7

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...

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 7. So we're done reducing.

There you have it! Here's the final answer to 80/2 + 1/7

80
2
+
1
7
=
281
7
© 2014 Randy Tayler