Standard Values for electronic components
Multiples of
10
12
15
18
21
27
33
39
42
47
51
56
62
68
72
75
81
92
100

eg: 10 M ohm,1.2 µF etc
 

If your calculator has sufficient mem, store these values in your calculator.

eg:] Save 10121518 as one No in the calculator memory. Most calculators like the casio Fx100 series have 6,  6 digit No memory.