SUBTRACTION is to be taught in the same way as Addition, viz. first by indicating the difference between the numbers by means of the common language, and then the subtraction is to be made from inspection by the eye.

Thus, in the first lesson we teach the table in the common way, and then by the eye, and similarly for all the lessons which follow.

8 9 10

We see, from the above examples, that when the lower figure is less than the one directly over it, we may suppose ten to be added to the upper figure.

If several figures are written by the side of each other, thus

we say, 6 from 11 leaves 5; then we add 1 to the next figure to the left and say, 5 from 12 leaves 7: we then add 1 to the 7 and say, 8 from 13 leaves 5: we then add 1 to the 3 and say, 4 from 8 leaves 4. We then bring down the figures 4 and 6, and find the result to be 644575.