Developing Computational Thinking through Scratch in Grades 2–5

Submitted by Yi Li, Science Teacher, Grades 2-5

In the Lower School STEM classes, our goal is not only to teach students how to use technology, but to help them develop computational thinking—the ability to break problems into parts, recognize patterns, design logical steps, test ideas, and revise their thinking. These skills support learning in computer science, mathematics, engineering, and everyday problem-solving.

Scratch provides an ideal environment for this work because it makes abstract thinking visible. When students connect blocks to control characters on the screen, they are learning how instructions, logic, and systems work together. From Grade 2 through Grade 5, students revisit the same core ideas while applying them in increasingly complex ways.

Grade 2
Students use ScratchJr and Kodable to learn the basics of coding. They explore the programming environment, control characters, backgrounds, and sounds, and practice sequences, loops, and simple conditions through stories, animations, and logic games.

Grade 3
In Grade 3, students transition to Scratch. We revisit the same ideas in a more powerful programming environment. They are introduced to the coordinate system to control where characters move on the screen. In a fun physical environment, it is actually easier for students to understand the complex math concepts. Students also practice loops, selection structures (if–then), sensing, and simple operators, allowing them to create interactive stories and games that respond to user input. 

Grade 4
In Grade 4, students learn how to combine different coding structures to build more complex systems. They use loops and conditions together, explore sensing in more depth, and learn to use variables and random numbers to create scores, timers, and unpredictable events. Students are also introduced to tools such as the pen and sound editor. Students who complete the required tasks are also challenged to use broadcasting and cloning to help different characters communicate and work together within a single program. 

Grade 5
Students design and program their own mini-games, integrating everything they have learned. They practice debugging, testing, and using available resources to explore new features, becoming more independent and confident problem solvers.