all the following patterns need to be accepted: 0, +0,-0, any integer, any integer preceded by + or - sign.

.3, 3.14, +3.14159, -3.14159, 0.123, -0.123, .123, +.123

12e+2, 7e-4, 6.3e2, 6.3e+2, 6.3e-2, -6.3e+2

I am a little bit confused about how to make the equation.