| 12 + 6 = 18 | 22 + 6 = 28 | 19 + 8 = 27 | |
| 54 + 9 = 63 | 56 + 7 = 63 | 22 + 8 = 30 | |
| 100 - 9 = 91 | 27 - 8 = 19 | 44 - 6 = 38, | &c. |
33. When the last two articles have been thoroughly studied, you will be able to find the sum of any numbers by the following process,[6] which is the same as that in (29).
Rule I. Place the numbers under one another, units under units, tens under tens, and so on.
II. Add together the units of all, and part the whole number thus obtained into units and tens. Thus, if 85 be the number, part it into 8 tens and 5 units; if 136 be the number, part it into 13 tens and 6 units (20).
III. Write down the units of this number under the units of the rest, and keep in memory the number of tens.
IV. Add together all the numbers in the column of tens, remembering to take in (or carry, as it is called) the tens which you were told to recollect in III., and divide this number of tens into tens and hundreds. Thus, if 335 tens be the number obtained, part this into 33 hundreds and 5 tens.
V. Place the number of tens under the tens, and remember the number of hundreds.
VI. Proceed in this way through every column, and at the last column, instead of separating the number you obtain into two parts, write it all down before the rest.
Example.—What is
1805 + 36 + 19727 + 3 + 1474 + 2008