# help on two-step solutions, quickly please!

• Nov 17th 2008, 06:47 PM
keebler
help on two-step solutions, quickly please!
So I've got to do finding the Least Common Multiple of rational decimals, and the examples are all telling me that you have to take the power that represents the greatest number of decimal places in any term of the equation. The examples say that for the problem 1.12c + 2.06 = 9.9. Since the greatest spot is 2 to the right of the decimal, it states that the power of ten that should be used is 10 for each number that has 2 to the right of the decimal. Two numbers have that, so it should be 10 x 10. It obviously says the LCM should be 100.

This is where I start having trouble. If a problem only ever goes one space to the right, what power of ten should be used? If all three numbers all have one space to the right, it should be that number times itself, times itself, right? So what the heck am I not getting?
• Nov 22nd 2008, 05:52 AM
HallsofIvy
Quote:

Originally Posted by keebler
So I've got to do finding the Least Common Multiple of rational decimals, and the examples are all telling me that you have to take the power that represents the greatest number of decimal places in any term of the equation. The examples say that for the problem 1.12c + 2.06 = 9.9. Since the greatest spot is 2 to the right of the decimal, it states that the power of ten that should be used is 10 for each number that has 2 to the right of the decimal. Two numbers have that, so it should be 10 x 10. It obviously says the LCM should be 100.

This is where I start having trouble. If a problem only ever goes one space to the right, what power of ten should be used? If all three numbers all have one space to the right, it should be that number times itself, times itself, right? So what the heck am I not getting?

I don't know what it is that you are not getting since applying what you said in the first paragraph works nicely. You said "you have to take the power that represents the greatest number of decimal places in any term of the equation." If you have one space to the right then that number is '1' and so you have to use $10^1= 10$. "If all three numbers all have one space to the right" then the greatest number of decimal places is still 1 so you still use $10^1= 1$. In the first example, everynumber went "2 places to the right" and you use $10^2= 100$ you did NOT say that because there are 3 such numbers you have to use it 3 times so why would you think that " If all three numbers all have one space to the right, it should be that number times itself, times itself"? It doesn't matter how many numbers you have, all that matters is the "largest" number of decimal places to the right.