math help

What is 100/50 + 1/7?

What is 100/50 + 1/7?

Here's how we add

100
50
+
1
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 1 by 50, and get 50, then multiply 50 by 7 and get 350.

1/7 times 50

The problem now has new fractions to add:

700
350
+
50
350

Step 2

Since our denominators match, we can add the numerators.

700 + 50 = 750

The sum we get is

750
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:

750
350
÷ 2 =
375
175

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

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

375
175
÷ 5 =
75
35

So far so good... let's try to divide by that number again.

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

75
35
÷ 5 =
15
7

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

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

And we're done! Here's the final answer to 100/50 + 1/7

100
50
+
1
7
=
15
7
© 2014 Randy Tayler