Make a multiplication table for Z5 (this should read Z sub 5)

Z5 multiplication table.

The Z5
congruence class consists of the numbers 0,1,2,3,4.

So
Multiplication any 2 numbers in z system is given below:

In Z5
system we represent numbers by the rule:

a*b =  remainder part of
a*b/5 . This means the system has numbers 0, 1,2,3 or 4.

Example 4
E  Z5  and 3 E Z5.

Therefore 4*3 = 12 = remainder of 12/5 =
2.

Similarly 4*2 = 8 = Remainder of (8/5) =
3

Similarly 4*1 = 4 = 4 only as (remainder of (4/5) =
4.

Similarly 0*4 = 0 obvious by the abve
reason.

Now we write table of multiplication under Z5
system:

(*  5 ) :      0        1         2          3        
4

    0     :     0        0         0          0        
0

    1     :     0         1        2         
3         4

    2     :     0         2        4          1        
3

    3     :     0         3        1          4        
2

    4     :     0         4        3          2        
1.