How add and subtracting is done to makethe mantissa positive?

To perform addition or subtraction involving mantissas in floating-point representation, first ensure that the exponents are the same by adjusting the mantissas accordingly. For addition, the mantissas are combined, and if the result is negative, it may require normalization, which can involve adjusting the exponent. For subtraction, the mantissa of the smaller number is subtracted from the larger, and similarly, if the result is negative, normalization is again necessary. In both cases, the goal is to maintain a positive mantissa while ensuring the overall representation remains accurate.