math help

What is 20/64 + 2/7?

What is 20/64 + 2/7?

This is how you add

20
64
+
2
7

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

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

20/64 times 7

Now for the second term. You multiply 2 by 64, and get 128, then multiply 64 by 7 and get 448.

2/7 times 64

This gives us a new problem that looks like so:

140
448
+
128
448

Step 2

Since our denominators match, we can add the numerators.

140 + 128 = 268

So what's the answer so far?

268
448

Step 3

Can this fraction be reduced?

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

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

268
448
÷ 2 =
134
224

Let's try dividing by that again...

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

134
224
÷ 2 =
67
112

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...

No good. 71 is larger than 67. So we're done reducing.

There you have it! Here's the final answer to 20/64 + 2/7

20
64
+
2
7
=
67
112
© 2014 Randy Tayler