math help

What is 45/4 + 3/10?

What is 45/4 + 3/10?

This is how to add

45
4
+
3
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 45 by 10, and get 450, then we multiply 4 by 10 and get 40.

45/4 times 10

Do the same for the second term. We multiply 3 by 4, and get 12, then multiply 4 by 10 and get 40.

3/10 times 4

The problem now has new fractions to add:

450
40
+
12
40

Step 2

Since our denominators match, we can add the numerators.

450 + 12 = 462

The sum we get is

462
40

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:

462
40
÷ 2 =
231
20

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. 23 is larger than 20. So we're done reducing.

And we're done! Here's the final answer to 45/4 + 3/10

45
4
+
3
10
=
231
20
© 2014 Randy Tayler