math help

What is 5/100 + 3/7?

What is 5/100 + 3/7?

This is how we add

5
100
+
3
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 5 by 7, and get 35, then we multiply 100 by 7 and get 700.

5/100 times 7

Now for the second term. You multiply 3 by 100, and get 300, then multiply 100 by 7 and get 700.

3/7 times 100

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

35
700
+
300
700

Step 2

Since our denominators match, we can add the numerators.

35 + 300 = 335

Answer:

335
700

Step 3

Now, do we need to simplify this fraction?

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

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:

335
700
÷ 5 =
67
140

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...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

No good. 71 is larger than 67. So we're done reducing.

Congratulations! Here's your final answer to 5/100 + 3/7

5
100
+
3
7
=
67
140
© 2014 Randy Tayler