math help

What is 4/8 + 3/10?

What is 4/8 + 3/10?

Here's how we add

4
8
+
3
10

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 10, and get 40, then we multiply 8 by 10 and get 80.

4/8 times 10

Now for the second term. You multiply 3 by 8, and get 24, then multiply 8 by 10 and get 80.

3/10 times 8

This gives us a new problem that looks like so:

40
80
+
24
80

Step 2

Since our denominators match, we can add the numerators.

40 + 24 = 64

That gives us an answer of

64
80

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:

64
80
÷ 2 =
32
40

Now, try the same number again.

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

32
40
÷ 2 =
16
20

Now, try the same number again.

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

16
20
÷ 2 =
8
10

Now, try the same number again.

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

8
10
÷ 2 =
4
5

Now, try the same number again.

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

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

No good. 5 is larger than 4. So we're done reducing.

Congratulations! Here's your final answer to 4/8 + 3/10

4
8
+
3
10
=
4
5
© 2014 Randy Tayler