Suppose you have entered in A1: 60% (the "%" is entered as well), in B1: 315,
then you could place in C1: =A1*B1 to compute the result. And if A2:B2, A3:B3
contains other pairs of percentages and numbers to be multiplied, you could
simply copy the formula in C1 down by dragging the fill handle at the bottom
right corner of C1 (the solid black square).