math help

What is 1/9 + 2/10?

What is 1/9 + 2/10?

Let's add

1
9
+
2
10

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 1 by 10, and get 10, then we multiply 9 by 10 and get 90.

1/9 times 10

Do the same for the second term. We multiply 2 by 9, and get 18, then multiply 9 by 10 and get 90.

2/10 times 9

The problem now has new fractions to add:

10
90
+
18
90

Step 2

Since our denominators match, we can add the numerators.

10 + 18 = 28

The sum we get is

28
90

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:

28
90
÷ 2 =
14
45

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...

No good. 17 is larger than 14. So we're done reducing.

Congratulations! Here's your final answer to 1/9 + 2/10

1
9
+
2
10
=
14
45
© 2014 Randy Tayler