math help

What is 100/50 + 2/7?

What is 100/50 + 2/7?

Here's how you add

100
50
+
2
7

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 100 by 7, and get 700, then we multiply 50 by 7 and get 350.

100/50 times 7

Now for the second term. You multiply 2 by 50, and get 100, then multiply 50 by 7 and get 350.

2/7 times 50

We now have a new problem, that looks like this:

700
350
+
100
350

Step 2

Since our denominators match, we can add the numerators.

700 + 100 = 800

That gives us the sum, which is

800
350

Step 3

Now, do we need to simplify this fraction?

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

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

800
350
÷ 2 =
400
175

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...

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

400
175
÷ 5 =
80
35

Let's try dividing by that again...

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

80
35
÷ 5 =
16
7

Let's try dividing by that again...

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 100/50 + 2/7

100
50
+
2
7
=
16
7
© 2014 Randy Tayler