math help

What is 8/10 + 4/8?

What is 8/10 + 4/8?

This is how you add

8
10
+
4
8

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 8 by 8, and get 64, then we multiply 10 by 8 and get 80.

8/10 times 8

Do the same for the second term. We multiply 4 by 10, and get 40, then multiply 10 by 8 and get 80.

4/8 times 10

The problem now has new fractions to add:

64
80
+
40
80

Step 2

Since our denominators match, we can add the numerators.

64 + 40 = 104

The sum we get is

104
80

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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

104
80
÷ 2 =
52
40

Let's try dividing by that again...

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

52
40
÷ 2 =
26
20

Let's try dividing by that again...

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

26
20
÷ 2 =
13
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 8/10 + 4/8

8
10
+
4
8
=
13
10
© 2014 Randy Tayler