Module – 10
ABACUS - MULTIPLICATION
INVOLVING ZEROExample : 405 x 307
a) Set the multiplier 405 in the extreme left.
b) For setting the multiplicand, count the digits of multiplier and multiplicand. Add one
digit for abacus. Totally we have 7 digits. Therefore, set multiplicand 307 in the right
side, the number 3 in the last but 7th column and so on.
c) Now, we are ready to multiply. Multiply the number 7 of the 307 and the number 4 of
the 405, i.e., 7 5 4 = 28. Set the product 28 in the immediate right of 7 in the right
side of the abacus. Keep your right hand on the number 8 of the product.
d) Next, 7 5 0 is 0. Therefore, skip the column where your right hand rests and move
both hands to the right and keep them on the hundreds and tens column respectively.
e) Multiply 5 5 7. That is 35. Place the 3 in the tens column and the number 5 in the
units column. Clear the number 7 of the multiplicand.
f) Since the multiplication has a zero in the middle, just leave it. Let us multiply the
number 3 of multiplicand with the number 4 of 405. 3 5 4 is 12. Set the number 12
on the immediate right of the multiplicand with right hand. Keep your right hand on
the 2 of the new number 12.
g) Next, 3 5 0 = 0. Therefore, skip that column and move both hands to right. Keep
them on the next consecutive columns. Multiply 3 5 5 i.e., 15. Set the number 1 in
the thousands column and 5 in the hundreds column.