Moroccan Foundation for Advanced Science, Innovation and Research

In this study, we aim to identify the difficulties in teaching and learning the concept of “fractions” among third-primary (3rd grade) and fourth-primary (4th garde) learners in Morocco. We used a sample of 139 pupils (70 3rd -primary pupils, 69 4th-primary pupils) and 4 teachers. We used a descriptive analytical methodology to treat the data collected through a supervised test (given to pupils) and a questionnaire (given to teachers). The results indicated that pupils in both third and fourth primary had major difficulties in recognizing fractions, representing them, and comparing them. third-primary pupils had difficulties in associating fractions with their written form and in recognizing them visually from geometric figures. On the other hand, although fourth-primary pupils showed progress, they continued to have difficulties when comparing fractions with different denominators, particularly in tasks involving equivalent fractions. Teachers also noted a lack of depth in their teaching practices, which were often limited to theoretical approaches without sufficient links to concrete activities. These results suggest the need for a more interactive and hands-on teaching approach aimed at promoting visual and practical understanding of fractions to reinforce the acquisition of these essential concepts.

This article describes the design, control, and implementation of a photovoltaic (PV) emulator using two-switch forward-converter topology. The system is designed to emulate the nonlinear electrical behavior of an actual PV panel under different environmental conditions including radiation level and temperature. The emulator provides galvanic isolation and also accurate current modulation to provide a safe yet reliable means of testing PV-related devices and algorithms within a laboratory setting. A dual-loop PI control is proposed to adjust the output current according to voltage feedback (VF), thus making accurate I–V and P–V curves achievable. Besides software simulation, a tailored printed circuit board (PCB) was fabricated. The simulation result demonstrated that the system can achieve a fast response and stable operation, with a maximum error percentage of about 2.1%, indicating high emulation fidelity, thereby providing an attractive platform for various evaluation purposes such as MPPT algorithms, inverters, and EMS.