math help

What is 5/100 + 2/7?

What is 5/100 + 2/7?

This is how you add

5
100
+
2
7

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

5/100 times 7

Do the same for the second term. We multiply 2 by 100, and get 200, then multiply 100 by 7 and get 700.

2/7 times 100

The problem now has new fractions to add:

35
700
+
200
700

Step 2

Since our denominators match, we can add the numerators.

35 + 200 = 235

This yields the answer

235
700

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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:

235
700
÷ 5 =
47
140

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...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

No good. 53 is larger than 47. So we're done reducing.

There you have it! Here's the final answer to 5/100 + 2/7

5
100
+
2
7
=
47
140
© 2014 Randy Tayler