math help

What is 4/10 + 2/5?

What is 4/10 + 2/5?

Here's how to add

4
10
+
2
5

Step 1

Now we need to make our denominators match.

10 goes into 5 evenly, so we only need to multiply one term to get a common denominator.

Multiply 2 by 2, and get 4, then we multiply 5 by 2 and get 10.

This gives us a new problem that looks like so:

4
10
+
4
10

Step 2

Since our denominators match, we can add the numerators.

4 + 4 = 8

So what's the answer so far?

8
10

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:

8
10
÷ 2 =
4
5

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...

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

There you have it! Here's the final answer to 4/10 + 2/5

4
10
+
2
5
=
4
5
© 2014 Randy Tayler