Most hobbyist would love to own a Goliath may you too would like one right?? so why? maybe because that it is big that it can grow up to 12inches. Well if Size Matters, why dont you consider The Brazilian Salmon Pink Tarantula? this guy grows fast and can grow about 10 inches (although mine is only 8-9 inches) making this a good start.
Reference Language | Libraries | Comparison | Changes. Double precision floating point number. On the Uno and other ATMEGA based boards, this occupies 4 bytes. That is, the double implementation is exactly the same as the float, with no gain in precision. On the Arduino Due, doubles have 8-byte (64 bit) precision.
Floats have only 6-7 decimal digits of precision. That means the total number of digits, not the number to the right of the decimal point. Unlike other platforms, where you can get more precision by using a double (e.g. up to 15 digits), on the Arduino, double is the same size as float. Floating point numbers are not exact, and may yield strange results when compared. For example 6.0 / 3.0 may not equal 2.0.