math help

What is 20/64 + 1/11?

What is 20/64 + 1/11?

Here's how you add

20
64
+
1
11

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 20 by 11, and get 220, then we multiply 64 by 11 and get 704.

20/64 times 11

Do the same for the second term. We multiply 1 by 64, and get 64, then multiply 64 by 11 and get 704.

1/11 times 64

So now our fractions look like this:

220
704
+
64
704

Step 2

Since our denominators match, we can add the numerators.

220 + 64 = 284

So the answer is:

284
704

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:

284
704
÷ 2 =
142
352

Let's try dividing by that again...

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

142
352
÷ 2 =
71
176

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...

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

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

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

No good. 73 is larger than 71. So we're done reducing.

There you have it! Here's the final answer to 20/64 + 1/11

20
64
+
1
11
=
71
176
© 2014 Randy Tayler