One teacher involved

Teacher Hugo takes a total of four classes for lesson number 76. This means that each class 'uses' a quarter of the teacher. For this reason the lesson with two weekly periods has a value of 0.5 from the perspective of class 1a

The situation can be calculated as follows:

(number of weekly periods) / (number of classes) = (value)

Using the example of lesson 76, this would be:

2 / 4 = 0.5