math help

What is 64/16 + 7/9?

What is 64/16 + 7/9?

Here's how you add

64
16
+
7
9

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 64 by 9, and get 576, then we multiply 16 by 9 and get 144.

64/16 times 9

Do the same for the second term. We multiply 7 by 16, and get 112, then multiply 16 by 9 and get 144.

7/9 times 16

So now our fractions look like this:

576
144
+
112
144

Step 2

Since our denominators match, we can add the numerators.

576 + 112 = 688

So the answer is:

688
144

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:

688
144
÷ 2 =
344
72

Let's try dividing by that again...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

344
72
÷ 2 =
172
36

Let's try dividing by that again...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

172
36
÷ 2 =
86
18

Let's try dividing by that again...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

86
18
÷ 2 =
43
9

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...

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 9. So we're done reducing.

There you have it! Here's the final answer to 64/16 + 7/9

64
16
+
7
9
=
43
9
© 2014 Randy Tayler