A mo-Roman sampler

Question

    Pluck some relatively easy mo-Roman mini-puzzles while there’s relatively easy pickin’s.

1. What two English words, taken as mo-Roman numerals, form the same number?

   Two words other than MILL and MIC, that is, which both form the number 1099 as an example.

           MILL   =   M + (−I ) + L + L   =   1000 − 1 + 50 + 50   =   1099
           MIC     =   M + (−I ) + C       =   1000 − 1 + 100       =   1099

   Mo-Roman numerals use the same digits as Roman numerals but allow infinite variation.   All digits may occur any number of times and in any order. A smaller digit counts negatively each time it occurs anywhere to the left of a larger digit.   Here are two more ways to form 1099.

       IDIDCI   =   (−I ) + D + (−I ) + D + C + I          =   −1 + 500 - 1 + 500 + 100 + 1       =  1099
     LVMCLIIII   =   (−L) + (−V) + M + C + L + I + I + I + I   =   −50−5+1000+100+50+1+1+1+1   =  1099

   Among variations of the number that solves this mini-puzzle are an everyday word and a somewhat technical (not technological) term that also spells a common abbreviation.
   
   

2. What is the simplest mo-Roman representation of zero?   (Meant to familiarize, not trick.)

   Simplest ?   The fewer the digits the simpler (M is simpler than XX).   For the same number of digits, compare largest digits (LXLI is simpler than VVCI because L is less than C).   Any further ambiguity is decided by persuasive ranting.
   
   

3. What is the simplest mo-Roman numeral whose value remains unchanged by removing its last digit?   (Meant to be more interesting than tricky.)

   A nonsolution, going from IV to I by removing V, fails because the value changes (from 4 to 1).
   
   

4. What is the simplest positive mo-Roman numeral whose value is negated by removing its first digit?

   A nonsolution, going from  VI I I I I IV = 4  to  I I I I I IV = −1  by removing V, fails because  −4 ≠ −1.
   
   

5. What is the simplest positive mo-Roman numeral whose value is negated by removing its last digit?

   A nonsolution, going from  I I I I I IVV = 4  to  I I I I I IV = −1  by removing V, fails because  −4 ≠ −1.
   
   

6. What is the simplest positive mo-Roman numeral whose value can be negated by appending a single digit?

   A nonsolution, going from  I I I I I I = 6  to  I I I I I IV = −1  by appending V, fails because  −6 ≠ −1.
   
   

7. What is the simplest positive mo-Roman numeral whose value can be negated by prepending (adding on the left) a single digit?

   A nonsolution, going from  I I I I I IX = 4  to  VI I I I I IX = −1  by prepending V, fails because  −4 ≠ −1.
   
   

8. What is the simplest positive mo-Roman numeral whose value is negated by reversing the order of its digits?

   A nonsolution, reversing  VI I I I I I = 11  to get  I I I I I IV = −1 , fails because  −11 ≠ −1.
   
   

9. What is the simplest mo-Roman representation of zero that
   • is asymmetric
   • also represents zero when reversed?

   A nonsolution, VVVVXX = 0, fails because its reverse, XXVVVV = 40, does not represent 0.
   
   

10. What is the simplest mo-Roman representation of zero that
    • is asymmetric
    • also represents zero when reversed
    • includes only one instance of its largest digit?

    The same nonsolution, VVVVXX = 0, fails both because its reverse does not represent 0 and because it contains two instances of its largest digit, X.
    
    

11. What is the simplest mo-Roman representation of zero that
    • is asymmetric
    • also represents zero when reversed
    • includes only one instance of its largest digit
    • begins and ends with different digits?

    That nonsolution, VVVVXX = 0, does begin and end with different digits, V and X, but again fails because its reverse does not represent 0 and it contains two instances of its largest digit.

Pick and pluck as you please.   Partial posts are welcome.   The mo-Roman the mo-merrier!

Answer 1

1 What two English words, taken as mo-Roman numerals, form the same number?

IM(apparently can be used as a noun) and DID = 999
[Intended answer, from Dan Russell: DIM = ID = 499]

2 What is the simplest mo-Roman representation of zero?

I believe the simplest/smallest answer is VVX because V being half of X is the best ratio to nullify the value quickly.

3 What is the simplest mo-Roman numeral whose value remains unchanged by removing its last digit?

VX removing the last X still gives 5.

4 What is the simplest positive mo-Roman numeral whose value is negated by removing its first digit?

XVVVX remove the first X and it goes from 5 to -5

5 What is the simplest positive mo-Roman numeral whose value is negated by removing its last digit?

VVVXX remove the last X and it goes from 5 to -5

6 What is the simplest positive mo-Roman numeral whose value can be negated by appending a single digit?

VVVXVV appending a X will go from 5 to -5

7 What is the simplest positive mo-Roman numeral whose value can be negated by prepending (adding on the left) a single digit?

LLCV goes from 5 to -5 by prepending a X

8 What is the simplest positive mo-Roman numeral whose value is negated by reversing the order of its digits?

XVVVVXV reverting the order will make it go from 5 to -5

9 What is the simplest mo-Roman representation of zero that
• is asymmetric
• also represents zero when reversed?

Yet again, not sure if the best but... VVCLLLLCX

10 What is the simplest mo-Roman representation of zero that
• is asymmetric
• also represents zero when reversed
• includes only one instance of its largest digit?

Seems a bit long, but maybe VIIIIIIIIIIXV is the best...

11 What is the simplest mo-Roman representation of zero that
• is asymmetric
• also represents zero when reversed
• includes only one instance of its largest digit
• begins and ends with different digits?

Assuming 10 is correct, perhaps XVVVVVVVVVVLVV is the best.

Answer 2

For mini-puzzle #1, how about

DIM = -500 -1 +1000 = 499

and

ID = -1 +500 = 499 (as in Freud)