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#### 3.7.9 Modes Tutorial Exercise 2

If the radix is 15 or higher, we can't use the letter ‘`e`’ to mark the exponent because ‘`e`’ is interpreted as a digit. When Calc needs to display scientific notation in a high radix, it writes ‘`16#F.E8F*16.^15`’. You can enter a number like this as an algebraic entry. Also, pressing `e` without any digits before it normally types `1e`, but in a high radix it types `16.^` and puts you in algebraic entry: `16#f.e8f <RET> e 15 <RET> *` is another way to enter this number.

The reason Calc puts a decimal point in the ‘`16.^`’ is to prevent huge integers from being generated if the exponent is large (consider ‘`16#1.23*16^1000`’, where we compute ‘`16^1000`’ as a giant exact integer and then throw away most of the digits when we multiply it by the floating-point ‘`16#1.23`’). While this wouldn't normally matter for display purposes, it could give you a nasty surprise if you copied that number into a file and later moved it back into Calc.