| | 1st Division | 2d Division | 3d Division | 4th Division | 5th Division |
| 1st part, 34 days, beginning with day | 5 Ahau | 5 Eb | 5 Kan | 5 Cib | 5 Lamat |
| 2d part, 18 days, beginning with day | 13 Ix | 13 Cimi | 13 Eznab | 13 Oc | 13 Ik |
| Total number of days | 52 | 52 | 52 | 52 | 52 |
Applying rule 4 (p. [253]), we have: 5 × 52 = 260, the exact number of days in a tonalamatl. The next tonalamatl (see lower part of pl. [28], that is, Dresden 15c) has 10 day signs arranged in two parallel columns of 5 each. This, at its face value, would seem to be divided into 10 divisions, and the calculations confirm the results of the preliminary inspection.
The tonalamatl opens with the day 3 Lamat. Adding to this the first black number, 12, the day reached will be 2 Ahau, of which only the 2 is recorded here. Adding to 2 Ahau the next black number, 14, the day reached will be 3 Ix. And since 14 is the last black number, this new day will be the beginning of the next division in the tonalamatl and will appear as the upper day sign in the second column.[[247]] Commencing with 3 Ix and adding to it the first black number 12, the day reached will be 2 Cimi, and adding to this the next black number, 14, the day reached will be 3 Ahau, which appears as the second glyph in the first column. This same operation if carried throughout will give the following outline of this tonalamatl:
| | 1st Division | 2d Division | 3d Division | 4th Division | 5th Division | 6th Division | 7th Division | 8th Division | 9th Division | 10th Division |
| 1st part, 12 days, beginning with day | 3 Lamat | 3 Ix | 3 Ahau | 3 Cimi | 3 Eb | 3 Eznab | 3 Kan | 3 Oc | 3 Cib | 3 Ik |
| 2d part, 14 days, beginning with day | 2 Ahau | 2 Cimi | 2 Eb | 2 Eznab | 2 Kan | 2 Oc | 2 Cib | 2 Ik | 2 Lamat | 2 Ix |
| Total number of days | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 |
Applying rule 4 (p. [253]) to this tonalamatl, we have: 10 × 26 = 260, the exact number of days in a tonalamatl.
The tonalamatl which appears in the middle part on plate [28]—that is, Dresden 15b—extends over on page 16b, where there is a black 13 and a red 1. The student will have little difficulty in reaching the result which follows: The last day sign is the same as the first, and consequently this tonalamatl is divided into four, instead of five, divisions:
| | 1st Division | 2d Division | 3d Division | 4th Division |
| 1st part, 13 days, beginning with day | 1 Ik | 1 Manik | 1 Eb | 1 Caban |
| 2d part, 31 days, beginning with day | 1 Men | 1 Ahau | 1 Chicchan | 1 Oc |
| 3d part, 8 days, beginning with day | 6 Cimi | 6 Chuen | 6 Cib | 6 Imix |
| 4th part, 13 days, beginning with day | 1 Ix | 1 Cauac | 1 Kan | 1 Muluc |
| Total number of days | 65 | 65 | 65 | 65 |
Applying rule 4 (p. [253]) to this tonalamatl, we have: 4 × 65 = 260, the exact number of days in a tonalamatl. The tonalamatls heretofore presented have all been taken from the Dresden Codex. The following examples, however, have been selected from tonalamatls in the Codex Tro-Cortesianus. The student will note that the workmanship in the latter manuscript is far inferior to that in the Dresden Codex. This is particularly true with respect to the execution of the glyphs.
The first tonalamatl figured from the Codex Tro-Cortesianus (see pl. [29]) extends across the middle part of two pages (Tro-Cor. 10b, 11b). The four day signs at the left indicate that it is divided into four divisions, of which the first begins with the day 13 Ik.[[248]] Adding to this the first black number 9, the day 9 Chuen is reached, and proceeding in this manner the tonalamatl may be outlined as follows: