Looking for patterns in the multiplication table mod n:

Finish the multiplication table handout by figuring out the table for Z5 and Z6

A unit is a number that has a multiplicative inverse,  You can find units by looking in the multiplication table to see if there is a 1 in the row.  If there is, that number is a unit.  Color/circle/highlight each unit in red or orange or yellow or pink.

A zero divisor is either of a pair of  numbers such that ab=0, but neither factor=0.  For example, 2 and 3 are not 0 in mod 6, but (2)(3)=0(mod 6). Color/circle/highlight each zero divisor in blue, green or purple.


x mod 6012345
0000000not a zero divisor because zero doesn't count as a zero divisor
10123451 is a unit because 1*1=1
20240242 is a zero divisor because 2*3=0 (and 2,3 both not zero)
30303033 is a zero divisor because 3*2=0 and 3*4=0
40420424 is a zero divisor because 4*3=0
50543215 is a unit because 5*5=1