Question

ok so i am trying to help my child learn the numer line and he raised a good point i cant explain..why do negative integers go to the left and positive number go to the right. While when in whole number or say decimals whole number go to the right of the decimal and tenths go the right of the decimals? this is confusing

Answer 1

There's no particular reason. We read left to right, so the number line ascends left to right. It's just how we express things.

Answer 2

oops i made a mistake. i meant why do wjole number go to the left of a decimal and tenths go to the right of the decimal while in a number line the lesser values are to the left

Answer 3

Hmm I don't think there is a really answer for that :)
I imagine it has a lot to do with how these systems were adopted over time.

But yah, like cholo mentioned, we read from left to right.

So we read the number and THEN the leftover.
On a graph, we read from left to right,
Imagine instead of graphing "x", you graphed time.

You want to show what happens as time progresses, from left to right.
So t=0 is somewhere on the left side, and you count upwards.

It seems intuitive to me at least. :D I dunno, just my thoughts!

Answer 4

The thing about the way the numbers are expressed is not really able to explained. It's conventional.

We could write 100 as 001, but we don't. It might be because we want to get an idea of the number by the first digit, so we make the first digit we read the largest one.

Answer 5

i guess i am just confused too because when we right say $1.40 the 40 cents is smaller than the dollar and it goes to the right yet when looking at a number line with negative integers the smaller lesser (negative) numbers start on the right.. it confused me with his thoughts

Answer 6

his way of looking at it the amount should be 40.1$ haha...

Answer 7

i get it his thought process but i was stumped for an answer

Answer 8

Each digit is relevant to a power of 10.

412.89 = 4*10^2 + 1 * 10^1 + 2 * 10^0 + 8 * 10^-1 + 9 * 10^-2

The number line and the way numbers are expressed are different things. They do not have to follow the same set of rules.

Answer 9

wow..that is over my head but thanks for trying..math was never my strong suit although I would like for it to be