What is 21/63 + 1/2?

This is how we add

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 21 by 2, and get 42, then we multiply 63 by 2 and get 126.

Now for the second term. You multiply 1 by 63, and get 63, then multiply 63 by 2 and get 126.

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

Step 2

Since our denominators match, we can add the numerators.

42 + 63 = 105

That gives us the sum, which is

Step 3

Now, do we need to simplify this fraction?

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

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:

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...

Are both the numerator and the denominator evenly divisible by 7? Yes! So we reduce it:

Let's try dividing by that again...

No good. 7 is larger than 5. So we're done reducing.

There you have it! Here's the final answer to 21/63 + 1/2