How to use scientific notation in js?

Question

var a = 5.0;
var b = a * 10e-12;
b *= 10e+12
print(b)

Why b equals 500 instead of 5?

As far as I know 10^(-12) equals to 1/(10^12), how can

Answer 1

10^-12 × 10¹² = 1

But what you wrote wasn't 10^-12, nor did you write 10¹².

What you wrote was 10 × 10¹² and 10 × 10^-12:

10 × 10¹² × 10 × 10^-12 = 100

100 × 5 = 500

Proper scientific notation is 1e-12 and 1e12. The e stands for "ten to the power of", so you don't need to multiply that value by ten again.