IV. ADDITION OF MULTIPLE DIGIT NUMBERS :
Example : 987 + 444
a) Set the number 987 in the extreme right of the abacus.
b) We are going to add 444 with 987. Start with higher value digits. That is, we
have to add 4 in the hundreds column, 4 in the tens column and 4 in the units
column.
c) Since there is no bead to add in the hundreds column, we cannot add directly.
d) We shall add one bead in the column which is the immediate left of number 9.
That is, number 1 is set in the thousands column. This means that we have
added 10 hundreds. That is, instead of adding 4 hundreds we have added 10
hundreds. Therefore, we have to subtract 6 hundreds from the hundreds columns.
e) Clear 6 from 9 in the hundreds column.
f) This process can continue with the next number (i.e., tens column numbers). As
in the previous case, it is not possible to add 4 with 8 directly in the tens
column.
g) Add one more bead in the hundreds column and clear 6 beads in the tens column.
That is, clear 6 from 8 in the tens column.
h) In the same way, to add the number 4 in the units column, add one bead in the
tens column and clear 6 from 7 in the units column. The answer is 1431.
EXERCISE
- 434 + 528
- 308 + 594
- 1234 + 49
- 7894 + 534
- 59819 + 9888
6. 60001 + 9979
7. 8940 + 1239
8. 9009 + 999
9. 100020 + 80728
10. 150711 + 4304
