For instance, to multiply any set of figures by 11--say 54--add the 5
and 4 together and put the 9 between the 5 and the 4. To multiply 1, 2,
3, 4, 5 and 6 by 11, do the same way, only carry your 10's. Thus 6 and 5
are 11, put down 1 before the 6; 5 and 4 are 9 and 1 to carry is 10; put
down the before the 16, etc. Again to multiply, say 18 9's by 9, bring
down a 1, then make 170's and a 9 out to the left. Again to square
numbers, call even 10's the body; call the rest the surplus,--104--add
surplus to body making it 108; now square the surplus (4) making 16 and
put it after the 108, or 10,816. This is simply taking advantage of the
10s. Take 33 and you will see. Here 3 is the surplus; add the surplus,
making 36; multiply 36 by 30, making 1,080; square the surplus, 3 times
3--9; add to 1,080--making 1,089. You see you get an even thirty to
multiply by and load up the sum to be multiplied sufficiently to
balance. Above 5 call it a deficit and go to your next 10 for your body.