math help

What is 72/63 + 4/8?

What is 72/63 + 4/8?

Here's how to add

72
63
+
4
8

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 72 by 8, and get 576, then we multiply 63 by 8 and get 504.

72/63 times 8

Now for the second term. You multiply 4 by 63, and get 252, then multiply 63 by 8 and get 504.

4/8 times 63

We now have a new problem, that looks like this:

576
504
+
252
504

Step 2

Since our denominators match, we can add the numerators.

576 + 252 = 828

Answer:

828
504

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide it by 2...

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

828
504
÷ 2 =
414
252

Let's try dividing by that again...

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

414
252
÷ 2 =
207
126

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

207
126
÷ 3 =
69
42

Let's try dividing by that again...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

69
42
÷ 3 =
23
14

Let's try dividing by that again...

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...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

No good. 17 is larger than 14. So we're done reducing.

There you have it! Here's the final answer to 72/63 + 4/8

72
63
+
4
8
=
23
14
© 2014 Randy Tayler