10+2 10-2 10*2 10/2 10/2.5 10^2 10**2 sqrt(100) 100**0.5 a = 4 a*5 a-10 b = c(3,4,5,6,7,8) mean(b) sum(b) prod(b) b d = matrix(b,ncol=3) d e = matrix(b,nrow=3) e