A caret (^) means to the power. And you've got to look at the mdb-row.

I read this as that you have a sign, 28 digits and a decimal point you can put anywhere you want.
So you go from -999999999999999999999999999. via -.00000000000000000000000000001, 0 +.0000000000000000000000000001 to +99999999999999999999999999999.

Also possible 12345678901234.12345678901234 and a lot of variations. In face 2 (sign) * 10^28 (possible combinations of digits) * 29 (positions of decimal point) different numbers, give or take a few (.000 = 0.00 = 00.0 = 000. = -0.00).
But nothing greater than 10 ^ 28 - 1.




For most applications, integer, long, single or double are good enough for numbers.

Kees