math help

What is 64/4 + 9/10?

What is 64/4 + 9/10?

This is how we add

64
4
+
9
10

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 64 by 10, and get 640, then we multiply 4 by 10 and get 40.

64/4 times 10

Now for the second term. You multiply 9 by 4, and get 36, then multiply 4 by 10 and get 40.

9/10 times 4

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

640
40
+
36
40

Step 2

Since our denominators match, we can add the numerators.

640 + 36 = 676

That gives us the sum, which is

676
40

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:

676
40
÷ 2 =
338
20

Let's try dividing by that again...

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

338
20
÷ 2 =
169
10

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...

No good. 11 is larger than 10. So we're done reducing.

There you have it! Here's the final answer to 64/4 + 9/10

64
4
+
9
10
=
169
10
© 2014 Randy Tayler