Hi everyone! Just wanted to take a minute to recap what we've learned so far in Chapter 4.
We first discussed the method for multiplying a decimal by a whole number. *Remember, you should not line up the decimals when you are multiplying - only when you're adding or subtracting.*
1) Set the problem up as though you were dealing with plain ol' whole numbers.
2) Solve (ignore the decimals for now - remember, we're pretending they are both whole numbers).
3) To place the decimal in your answer:
First, count how many numbers after the decimal in the original problem.
Then, going from right to left in your answer, count that many spaces over and put your decimal there.
Example:
4.23 ---> There are two numbers after the decimal here.
x 6
2538 ---> Now, going from right to left, put the decimal two places from the end.
Answer: 25.38
Today we talked about multiplying one decimal by another. *Remember, don't line up the decimals since we're multiplying!*
This method is exactly the same as the method for multiplying a decimal by a whole number.
1) Set the problem up.
2) Solve just like they're whole numbers (ignore the decimal).
3) How many numbers (TOTAL) are there after all the decimals in your problem? Count them up, and then
place the decimal that many places over in your answer.
Example:
3.65 ---> There are two numbers after the decimal here.
x 2.5 ---> There is one number after the decimal here.
9125 ---> Now, going from right to left, put the decimal three places from the end, since we counted
3 numbers total after decimal points in our problem.
Answer: 9.125
Try checking your answers with a calculator when doing your homework.
Extra Credit Question (you must show all work to receive credit):
4.42
x 9.8
