math help

What is 64/4 + 7/9?

What is 64/4 + 7/9?

Here's how to add

64
4
+
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 4 by 9 and get 36.

64/4 times 9

Do the same for the second term. We multiply 7 by 4, and get 28, then multiply 4 by 9 and get 36.

7/9 times 4

So now our fractions look like this:

576
36
+
28
36

Step 2

Since our denominators match, we can add the numerators.

576 + 28 = 604

Now we have an answer.

604
36

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:

604
36
÷ 2 =
302
18

Let's try dividing by that again...

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

302
18
÷ 2 =
151
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 64/4 + 7/9

64
4
+
7
9
=
151
9
© 2014 Randy Tayler