math help

What is 20/64 + 3/7?

What is 20/64 + 3/7?

This is how we add

20
64
+
3
7

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 20 by 7, and get 140, then we multiply 64 by 7 and get 448.

20/64 times 7

Do the same for the second term. We multiply 3 by 64, and get 192, then multiply 64 by 7 and get 448.

3/7 times 64

The problem now has new fractions to add:

140
448
+
192
448

Step 2

Since our denominators match, we can add the numerators.

140 + 192 = 332

The sum we get is

332
448

Step 3

The last step is to reduce the fraction if we can.

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:

332
448
÷ 2 =
166
224

Now, try the same number again.

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

166
224
÷ 2 =
83
112

Now, try the same number again.

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

No good. 89 is larger than 83. So we're done reducing.

Congratulations! Here's your final answer to 20/64 + 3/7

20
64
+
3
7
=
83
112
© 2014 Randy Tayler