math help

What is 100/50 + 5/7?

What is 100/50 + 5/7?

Let's add

100
50
+
5
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 100 by 7, and get 700, then we multiply 50 by 7 and get 350.

100/50 times 7

Do the same for the second term. We multiply 5 by 50, and get 250, then multiply 50 by 7 and get 350.

5/7 times 50

The problem now has new fractions to add:

700
350
+
250
350

Step 2

Since our denominators match, we can add the numerators.

700 + 250 = 950

This yields the answer

950
350

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:

950
350
÷ 2 =
475
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:

475
175
÷ 5 =
95
35

Let's try dividing by that again...

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

95
35
÷ 5 =
19
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 + 5/7

100
50
+
5
7
=
19
7
© 2014 Randy Tayler