math help

What is 100/50 + 9/11?

What is 100/50 + 9/11?

This is how you add

100
50
+
9
11

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 100 by 11, and get 1100, then we multiply 50 by 11 and get 550.

100/50 times 11

Do the same for the second term. We multiply 9 by 50, and get 450, then multiply 50 by 11 and get 550.

9/11 times 50

The problem now has new fractions to add:

1100
550
+
450
550

Step 2

Since our denominators match, we can add the numerators.

1100 + 450 = 1550

This yields the answer

1550
550

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:

1550
550
÷ 2 =
775
275

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:

775
275
÷ 5 =
155
55

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:

155
55
÷ 5 =
31
11

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. So next you try the next prime number, which is 13...

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

And we're done! Here's the final answer to 100/50 + 9/11

100
50
+
9
11
=
31
11
© 2014 Randy Tayler