When counting the values of a statistical variable, the number of values that corresponds to a given characteristic or that belongs to a particular class of values.
(A) If the attribute studied is discrete, the tally of a value x of this characteristic is the number of individuals for which the value of the characteristic is x.
Example
DISTRIBUTION IN A CLASS OF 40 STUDENTS
| Boys | Girls | TOTAL | |
| Wears glasses | 13 | 8 | 21 |
| Do not wear glasses | 9 | 10 | 19 |
| TOTAL | 22 | 18 | 40 |
Total tally: 40 students
Partial tally of boys: 22 students
Partial tally of girls: 18 students
Partial tally of students who wear glasses: 21 students
Partial tally of girls who wear glasses: 8 students
(B) If the characteristic studied is continuous, the tally of a class C is the number n of individuals for which the value of the characteristic belongs to the class C.
Example
DISTRIBUTION IN A CLASS OF 40 STUDENTS
| Height (cm)/ Mass(kg) |
[120, 130) | [130, 140) | [140, 150) | [150, 160) | [160, 170) | TOTAL |
| [45, 55) | 6 | 4 | 3 | 0 | 1 | 14 |
| [55, 65) | 4 | 3 | 5 | 2 | 0 | 14 |
| [65, 75) | 2 | 2 | 5 | 1 | 2 | 12 |
| TOTAL | 12 | 9 | 13 | 3 | 3 | 40 |
Total tally: 40 students
Partial tally of the group of students whose mass is located in the interval [140, 150) is 13 students
Partial tally of the group of students whose height is located in the interval [65, 75) is 12 students
The partial tally of the group of students whose mass belongs in the interval [140, 150) and whose height belongs to the interval [65, 75) is 5 students