If a numeric literal is in front of certain types of expressions, then the two are multiplied:
int x=2; real y=2.0; real cm=72/2.540005; write(3x); write(2.5x); write(3y); write(-1.602e-19 y); write(0.5(x,y)); write(2x^2); write(3x+2y); write(3(x+2y)); write(3sin(x)); write(3(sin(x))^2); write(10cm);
This produces the output
6 5 6 -3.204e-19 (1,1) 8 10 18 2.72789228047704 2.48046543129542 283.464008929116