In short, when two integers with like signs are added the result takes the same sign
and when two integers with unlike signs are added then the result takes the sign of
the integer with greater magnitude.
- Subtraction of integers
Integers are compatible for subtraction also. In subtraction the smaller integer is to
be subtracted from the greater integer irrespective of the sign and the resultant must
have the sign of the greater integer.
Subtraction of integers may also be taught orally assisted with necessary Braille text
material.
- Reciprocal
For any number other than zero, its reciprocal is obtained by interchanging the positions
of its numerator and the denominator.
Note that if the denominator of a number is not given then it is understood that the
denominator is equal to 1. Any number with its denominator as 1 is not going to
change its value even if it is not written and hence writing the denominator if it is 1
is not mandatory.
For a number ba its reciprocal is ab. The idea could be explained to the child orally
with the typed Braille text.
- Additive inverse
While adding two integers if the resultant is equal to zero, then the two integers
are said to be the additive inverses of each other.
Note that the additive inverse of an integer is nothing but the same integer with the
opposite sign. That is, if 4 is the given integer then its additive inverse is -4.
The idea of additive inverse can be taught to the child orally. To enhance the
understanding level of the child, the idea of negative numbers must be explained