math help

What is 100/50 + 7/9?

What is 100/50 + 7/9?

Here's how you add

100
50
+
7
9

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 9, and get 900, then we multiply 50 by 9 and get 450.

100/50 times 9

Do the same for the second term. We multiply 7 by 50, and get 350, then multiply 50 by 9 and get 450.

7/9 times 50

The problem now has new fractions to add:

900
450
+
350
450

Step 2

Since our denominators match, we can add the numerators.

900 + 350 = 1250

The sum we get is

1250
450

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:

1250
450
÷ 2 =
625
225

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:

625
225
÷ 5 =
125
45

Now, try the same number again.

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

125
45
÷ 5 =
25
9

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 9. So we're done reducing.

Congratulations! Here's your final answer to 100/50 + 7/9

100
50
+
7
9
=
25
9
© 2014 Randy Tayler