How numbers are represented in A+?

The machines on which A+ is run represent numbers in binary (base 2), for efficient storage and computation. A+ (via C) represents integers in 32 bits (binary digits) and floating-point numbers in 64. The largest integer representable in this way is (2*31)-1 and the smallest is ¢2*31 (-2147483648); the greatest magnitude representable as a floating-point number is approximately 1.7977e+308.

In display and print, of course, A+ represents numbers in decimal. People tend to think in decimal and their input is usually decimal. Numbers like .1 and .01 seem exactly representable intrinsically (as they are in decimal), but, in fact, these numbers cannot be exactly represented in binary, and decimal to binary and binary to decimal conversions are one source of imprecision. Read more from http://www.aplusdev.org/APlusRefV2_9.html