Digits

the initial bag of units being the symbols 0 through 9.

picture of dots for each digit, grouping those in smaller amounts when possible (6 as two three dots, but seven as just one row).

sub 1

sub 2

sub 3

sub 4

sub 5

sub 6

sub 7

Number as Matching
Pebbles of Various Sizes Digits
Carry Overs
Units Base Representations
Largest Number