Maths- Gym for Brainiacs

Hello, is there anybody out there? I see this thread has been dead for a while, but ill ask this here anyway.

I have a question about dividing decimal numbers, something that's been driving me nuts for the last hour. Ok, the basic principles of division are clear, you want to find what goes into a number a given amount of times, ie 20/5 is asking what goes into 20 five times. Whole numbers are easy, even dividing a whole number by a part number is easy, you just have to think about it a different way, ie 50/0.1 just think how many times 0.1 goes into 50, so logically in that case the quotient is bigger than the dividend.

But I don't know how to reconcile this principle to dividing one part number by another. For example, 0.001/0.02, my calculator will tell me the answer is 0.05. What I don't understand is how 2 hundredths goes into 1 thousandth 5 hundredth times.

I can understand 1 tenth going into 50 five hundred times, because there the divisor is smaller than the dividend. But in this case the divident, 1000th, is smaller than the divisor, 100th, so how is it 100th goes into 1000th 5 times?

loooooool didn't even understand what you just said.
Math is such an ass. Will probably fail my uni courses big time if I have to do it there.

DuringTheWar wrote:Hello, is there anybody out there? I see this thread has been dead for a while, but ill ask this here anyway.

I have a question about dividing decimal numbers, something that's been driving me nuts for the last hour. Ok, the basic principles of division are clear, you want to find what goes into a number a given amount of times, ie 20/5 is asking what goes into 20 five times. Whole numbers are easy, even dividing a whole number by a part number is easy, you just have to think about it a different way, ie 50/0.1 just think how many times 0.1 goes into 50, so logically in that case the quotient is bigger than the dividend.

But I don't know how to reconcile this principle to dividing one part number by another. For example, 0.001/0.02, my calculator will tell me the answer is 0.05. What I don't understand is how 2 hundredths goes into 1 thousandth 5 hundredth times.

I can understand 1 tenth going into 50 five hundred times, because there the divisor is smaller than the dividend. But in this case the divident, 1000th, is smaller than the divisor, 100th, so how is it 100th goes into 1000th 5 times?

Read this first, son:
http://en.wikipedia.org/wiki/Scientific_notation


then this


0.001/0.02 = 10^(-3)/(2*10^(-2))=1/2 * 10^(-3+2)= 1/2 * 10^(-1) = 1/2*1/10 = 1/20 = 0.05

The easier way is to multiply with the highest 10 exponent. In case of 0.001/0.02 * 1000/1000 = 1/20
1000/1000 = 1 so by multiplying you don't change the result => allowed.

Babun got another question. Lets say you have two expressions, 2x + 5, and -1/2 + 3x. You are asked to add the expressions. So you start by combining like terms, 2x + 3x = 5x. But what do you do with the fraction that has a minus sign in front of it? Do you just subtract positive 1/2 from 5 as that is the same as adding negative 1/2 to 5? How would you write it?

5 + (-1/2) = 5 - 1/2 = 4 1/2

(2x + 5) + (-1/2 + 3x) = 5x + 4 1/2

http://ichef.bbci.co.uk/news/660/media/images/82299000/jpg/_82299333_24e94c5d-dc7b-4590-8f46-29d0da74c8b8.jpg

Babun, RO, Spanky pls respond

I love that one.

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