What digit appears in the units place in the number obtained when 2320 is multiplied out?
A. 1
B. 2
C. 4
D. 6
E. 8
Look for the pattern in the last digits in all the powers of 2.
The series starts out 2...4...8...16...32....64...128..256...
Already the pattern is clear; the last digits repeat in a pattern 2,4,8,6,2,4,8,6, etc.
Every power that is a multiple of 4 will end in a 6 . 320 is a multiple of 4.