decimal numbers

[static crater]

Anyways i am gonna say it again. Basically i dont understand those digits after .

I was taught that 1.9 equals 1.90, and that 1.99 plus 0.01 becomes 2. I dont really see why. There're some numbers with large digits. An example, pi.

1.1234 this for example. 1234 is higher than 99

But it keeps as 1 (left number)

Why not another number?

I need a detailed and neat explanation

And a link if possible

I tried googling before coming here but didnt find what i wanted

Anyway thanks

[sharp grove]

take number 686

it's 600 + 80 + 6

similarly 6.86 means 6 + 8/10 + 6/100

numbers that you can write are special, most numbers are not like that

like they are just not a sum of powers of 10

i guess that's it

..
and like some numbers you can write if you repeat the same string of digits, like 1/7 is
0.142857142857142857142857...
any time you divide two whole numbers it's going to start repeating, and vice versa, if it repeats like that, you can get it with 2 numbers divided

so like they are almost special, you can't write them neatly like 6.86 but you can at least write them: 1/7 = 0.(142857) you highlight the part that repeats

and non special numbers you can't write like pi are the majority

[static crater]

@sharp grove i got u, so what's 1.9?