math help

What is 100/100 + 5/7?

What is 100/100 + 5/7?

This is how you add

100
100
+
5
7

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 100 by 7, and get 700, then we multiply 100 by 7 and get 700.

100/100 times 7

Do the same for the second term. We multiply 5 by 100, and get 500, then multiply 100 by 7 and get 700.

5/7 times 100

So now our fractions look like this:

700
700
+
500
700

Step 2

Since our denominators match, we can add the numerators.

700 + 500 = 1200

Now we have an answer.

1200
700

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:

1200
700
÷ 2 =
600
350

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:

600
350
÷ 2 =
300
175

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...

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

300
175
÷ 5 =
60
35

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

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

60
35
÷ 5 =
12
7

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. So next you try the next prime number, which is 11...

No good. 11 is larger than 7. So we're done reducing.

And we're done! Here's the final answer to 100/100 + 5/7

100
100
+
5
7
=
12
7
© 2014 Randy Tayler