Designing an E-Learning Environment in the Light of the Generative Learning Model (G.L.M) and Its Effectiveness in Developing Numerical Sense Skills for the Second Level of the Secondary Grade Students in Riyadh City

The current study aimed at designing an electronic learning environment in the light of the Generative Learning Model (G.L.M) and identifying its efficiency in developing the numerical sense for the 2nd–level secondary school students.
The sample comprised two equal groups of 2nd - level students (Curriculum System) at Al Shoura Secondary School in Riyadh. The experimental group comprised (30) students who were studying in an electronic environment according to the G.L.M, while the controlling group were (30) students. Both groups studied the same unit constructed upon the G.L.M in a paper form.
The researcher prepared two tests to measure the skills of numerical sense with the aim to identify the degree to which the 2nd-level students, after studying the unit: “Series and Sequences” In the maths curriculum (4). After implementing the experiment, the researcher concluded the following:
-There were not statistically significant differences at  between students’ mean marks in both groups (experimental and controlling) regarding post-test of numerical sense skills. 
-There were statistically significant differences at  between students’ mean marks in both groups (experimental and controlling) regarding pre/post-test performance of numerical sense skills, and the size of the effect is great.
In the light of these findings, the researcher recommended benefiting from electronic learning environments to facilitate learning maths contents, and to implement these environments to help teaching process succeed by way of using new teaching strategies. Also, the researcher recommended focusing on paying attention to measuring numerical sense skills at advanced levels which require communicative and mental capacity that matches the mathematical concept expansion and depth, and to be applied in real problems, whether direct or compound ones