math help

What is 100/50 + 2/9?

What is 100/50 + 2/9?

Here's how to add

100
50
+
2
9

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 100 by 9, and get 900, then we multiply 50 by 9 and get 450.

100/50 times 9

Now for the second term. You multiply 2 by 50, and get 100, then multiply 50 by 9 and get 450.

2/9 times 50

This gives us a new problem that looks like so:

900
450
+
100
450

Step 2

Since our denominators match, we can add the numerators.

900 + 100 = 1000

That gives us an answer of

1000
450

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

1000
450
÷ 2 =
500
225

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:

500
225
÷ 5 =
100
45

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:

100
45
÷ 5 =
20
9

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 9. So we're done reducing.

And we're done! Here's the final answer to 100/50 + 2/9

100
50
+
2
9
=
20
9
© 2014 Randy Tayler