FOUR FUNDAMENTAL OPERATIONS
- Four fundamental operations
The four fundamental operations on numbers are addition, subtraction, multiplication
and division. Addition is the process of combining two or more numbers into one
number. Subtraction is the reverse process of addition. In subtraction, from a given
number a smaller number is taken away and the remainder is found. Multiplication is
repeated addition of the same number. Division is repeated subtraction of the same
number. - Tips for performing the four fundamental operations
In performing the four fundamental operations, the following tips may be of help in
enabling the child to perform the activity with ease.
a. While adding numbers it will be easier if complements of 10 with respect to unit
digits are understood.b. To add 9 with a number, add 10 and subtract 1 in abacus.
To add 99 with a number, add 100 and subtract 1.
To add 999 with a number, add 1000 and subtract 1.
Similarly, to add 97 add 100 and subtract 3. To add 996 with a number, add 1000
and subtract 4.c. (i) To multiply a number by 5, multiply the number by 10 and then divide the
result by 2.