The idea of a number line is to be taught to the child orally along with the provision
of a tactile number line prepared with a thick sheet of paper. As the child explores the
number line, he/she will be able to understand the nature of the different numbers
both to the right and left of zero in the number line.
- Integers
Positive numbers, negative numbers and zero together form the set of integers.
The set of integers is denoted as Z.
Hence, Z = { ..., -3, -2, -1, 0, +1, +2, + 3, ...}
In the set of integers +1, +2, +3,...are called as positive integers and -1, -2, -3, ...
are called as negative integers. Note that zero is neither positive nor negative.
Note : Positive numbers can be written without the ‘ + ‘ sign also.
The idea could be taught to the child with the assistance of a tactile number line.
Related ideas such as the value of the digits may also be explained to the child orally.
Enable the child to understand that on the positive side, farther the digit is from zero,
greater is its value and on the negative side the closer the digit to zero, greater is its
value. Also, the ideas of ‘greater than’ and ‘less than’ may also be taught to the child
simultaneously with the same tactile number line.
- Addition of Integers
Integers are compatible for addition. The sum of two positive integers is a positive
integer and the sum of two negative integers is a negative integer. Also, if a negative
integer and a positive integer are added then the resulting integer will take the sign
of the integer which is greater in magnitude.
To add a positive integer with a negative integer, subtract the smaller integer from
the greater integer without considering the sign and to the result affix the sign of the
greater integer.
