Question

describe the relationship between the 2s in 75,222

Answer 1

The first '2' represents two hundred(200)
The second '2' represents twenty(20)
The third/last '2' represents two(2)

200+20+2=222
2 is a tenth of 20 (2x10=20)
20 is a tenth of 200 (20x10=200)

Answer 2

By definition, each position of the digit represents multiplication of that digit and number $10^{DigitPosition - 1}$
Positions are counted from right to left! The more we go from right to left digits have "heavier value".

For example first digit (the one on the right) represents number of units, second one (middle one) represents number of tens and third one (first from the left) represents number of hundreds. 

Further explanation: Third one (first from the left) represents number of hundreds because $10^{3-1}$ = 100