MCMLXXXVI or in more familiar format: 1986...We learned about the Roman numeral system and it's one great deficiency...they did not have Zero. For years and years I have taught using number lines and enjoyed sharing the old Schoolhouse Rocks videos...who remembers "Zero my hero"? This became amazingly apparent (the hero part) when the Number Devil explains the need for zero. Let's say that zero was absent...and your problem was 1-2=? Without the Zero the number line would show that the answer is -2 !! That shows that there is something missing...a missing number...ZERO!
At the end Robert (our under dog) is asked to "produce" the number 1986. This brings up expanded notation and Robert begins with 6X1=6 and 8x10=80 then 9x100-900 and finally 1x1000=1000...altogether 6+80+900+1000=1986...he has "produced" the number 1986.