Roman numerals greater than 1000

The rule for Roman numerals is that you cannot use more than three of the same symbol in a row. We know now that the way to remember the symbols is by remembering:

'I Value Xylophones Like Cows Do Milk'.
$I=1$ , $V=5$ , $X=10$ , $L=50$ , $C=100$ , $D=500$ , $M=1000$

numerals above 1000 example 1
But 4000 would then = $MMMM$ and you can't have more than three of the same symbol in a row.

The Romans got over this by putting a dash over any symbol to represent 1000 times the value of that symbol.

(Also note that Romans sometimes used an $M$ and sometimes $bar I$ but they mean the same thing).

$I$ = 1

$V$ = 5

$X$ = 10

$L$ = 50

$C$ = 100

$D$ = 500

$M$ = 1000

$bar I$ = 1000 x 1 = 1000

$bar V$ = 1000 x 5 = 5,000

$bar X$ = 1000 x 10 = 10,000

$bar L$ = 1000 x 50 = 50,000

$bar C$ = 1000 x 100 = 100,000

$bar D$ = 1000 x 500 = 500,000

$bar M$ = 1000 x 1000 = 1 million

The number 4000 thus becomes:

4000 = $Mbar V$

4001 = $Mbar VI$

4002 = $Mbar VII$

4003 = $Mbar VIII$

4004 = $Mbar VIV$