math help

What is 100/50 + 3/7?

What is 100/50 + 3/7?

This is how to add

100
50
+
3
7

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we 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 3 by 50, and get 150, then multiply 50 by 7 and get 350.

3/7 times 50

So now our fractions look like this:

700
350
+
150
350

Step 2

Since our denominators match, we can add the numerators.

700 + 150 = 850

So the answer is:

850
350

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

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:

850
350
÷ 2 =
425
175

Now, try the same number again.

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:

425
175
÷ 5 =
85
35

Now, try the same number again.

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

85
35
÷ 5 =
17
7

Now, try the same number again.

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

No good. 11 is larger than 7. So we're done reducing.

Congratulations! Here's your final answer to 100/50 + 3/7

100
50
+
3
7
=
17
7
© 2014 Randy Tayler