math help

What is 4/40 + 2/3?

What is 4/40 + 2/3?

Here's how to add

4
40
+
2
3

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 4 by 3, and get 12, then we multiply 40 by 3 and get 120.

4/40 times 3

Now for the second term. You multiply 2 by 40, and get 80, then multiply 40 by 3 and get 120.

2/3 times 40

This gives us a new problem that looks like so:

12
120
+
80
120

Step 2

Since our denominators match, we can add the numerators.

12 + 80 = 92

That gives us an answer of

92
120

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:

92
120
÷ 2 =
46
60

Now, try the same number again.

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

46
60
÷ 2 =
23
30

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...

No good. 29 is larger than 23. So we're done reducing.

Congratulations! Here's your final answer to 4/40 + 2/3

4
40
+
2
3
=
23
30
© 2014 Randy Tayler