The exponent is the number of digits the radix point has moved past: if it moves left then the exponent is negative, but if it moves right then it is positive. As above, making 1.45 into 145 requires you to multiply by 100, so the exponent is 2 as formula_3. Equally, turning 1101.0111 (13.4375) into 1101 0111 (215) requires you to move the radix point four columns to the right, so the exponent is 4; this can be verified in decimal as formula_4.