〈ADDITION.〉
The process of Addition includes two distinct parts—1st. The first consists of the addition of any one digit to another digit; 2nd. The second consists in carrying the tens to the next digit above.
Let us take the case of the addition of the two following numbers, in which no carriages occur:—
- 6023
- 1970
- 7993
It will be observed that, in making this addition, the mind acts by successive steps. The person adding says to himself—
- 0 and 3 make three,
- 7 and 2 make nine,
- 9 and 0 make nine,
- 1 and 6 make seven.
〈CARRIAGE.〉
In the following addition there are several carriages:—
- 2648
- 4564
- 7212
The person adding says to himself—