math help

What is 28/100 + 4/10?

What is 28/100 + 4/10?

This is how you add

28
100
+
4
10

Step 1

Our denominators (bottom numbers) don't match, so we can't add yet.

Since 10 is evenly divided by 100, we can multiply just one term to get a common denominator.

Multiply 4 by 10, and get 40, then we multiply 10 by 10 and get 100.

4/10 times 10

The problem now has new fractions to add:

28
100
+
40
100

Step 2

Since our denominators match, we can add the numerators.

28 + 40 = 68

The sum we get is

68
100

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:

68
100
÷ 2 =
34
50

Now, try the same number again.

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

34
50
÷ 2 =
17
25

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...

No good. 19 is larger than 17. So we're done reducing.

Congratulations! Here's your final answer to 28/100 + 4/10

28
100
+
4
10
=
17
25
© 2014 Randy Tayler