f) Example : 32.79 + 425.692
First set the number 32.76 in the abacus. Here you have only 3 digits after the
decimal point. Hence, fix the decimal point after the first dot in the right side of the
abacus.
g) Add the number 425.692 as you do in the normal addition. In the first number, you
do not have hundreds column. Set the number 4 (hundreds column) of the second
number which should be set in the abacus. Always remember that addition should
be made only with the corresponding digits. This is true for decimals also. For
convenience, zero can be added before or after the number to level decimal
points in both the numbers. For example, in the above sum, 32.76 can be treated
as 032.760.
In problems dealing with decimal points, the digits will not appear in the respective units,
tens, and hundreds columns of the abacus since the dots of the separation bar are used for
setting the whole number and decimal portions of the numbers. You should remember that
the positions of the numbers should be treated only with respect to the dots used for
setting the whole number and the decimal portion. This is the major difference between
normal addition and decimal addition.
EXERCISE
1) 43.56 + 56.987
2) 567.001 + 34.78
3) 651.8 + 23.8
4) 43.00001 + 32.65432
5) 49126.543 + 23.4567
6) 23.4951 + 41.90
7) 43.8905 + 45.76
8) 32.76 + 457.32
9) 23.87 + 41.76
10) 41.888 + 2.42