Practical -2 ( Integers )

Aim: To find the sum of given integers - -

a) (+1)+(-1)

b) 8+4

c) (-3)+(-5)

d) 3+(-5)

Material required: Two different coloured bindies and a sketch pen.

Procedure: 

Let one red colour bindi = +1

& One black colour bindi = -1

Case 1: (+1)+(-1)

a) Stick one red colour bindi to represent (+1) and one black colour bindi to represent (-1). b) Both the different colour bindies cancel each other.

Thus, (+1)+(-1)=0

Case II: 8+4

a) Stick eight red colour bindies to represent (+8) and again stick four red colour bindies to represent (+4). b) All the same colour bindies are added together.

Thus, (+8)+(+4)=+12

Case III: (-5)+(-3)

a) Stick five black colour bindies to represent (-5) and again stick three black colour bindies to represent (-3).

b) All the same colour bindies are added together.

Thus, (-5)+(-3)=(-8)

Case IV: 3+(-5)

a) Stick three red colour bindies to represent (+3) and stick five black colour bindies to represent (-5). 

b) All different colour bindies cancel each other and thus, two black colour bindies are left.

Thus, 3+(-5)=(-2)

Result:

a) (+1)+(-1)=0

b) 8+4=12

c) (-5)+(-3)=(-8)

d) 3+(-5)=(-2)