math help

What is 100/100 + 9/11?

What is 100/100 + 9/11?

This is how we add

100
100
+
9
11

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 11, and get 1100, then we multiply 100 by 11 and get 1100.

100/100 times 11

Do the same for the second term. We multiply 9 by 100, and get 900, then multiply 100 by 11 and get 1100.

9/11 times 100

So now our fractions look like this:

1100
1100
+
900
1100

Step 2

Since our denominators match, we can add the numerators.

1100 + 900 = 2000

Now we have an answer.

2000
1100

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:

2000
1100
÷ 2 =
1000
550

Now, try the same number again.

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

1000
550
÷ 2 =
500
275

Now, try the same number again.

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

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

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

500
275
÷ 5 =
100
55

Now, try the same number again.

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

100
55
÷ 5 =
20
11

Now, try the same number again.

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

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

No good. 13 is larger than 11. So we're done reducing.

Congratulations! Here's your final answer to 100/100 + 9/11

100
100
+
9
11
=
20
11
© 2014 Randy Tayler