Introduction to Block Coding with Scratch

Scratch is a free, visual programming tool created by MIT. Instead of typing lines of code, you snap colored blocks together — just like building with LEGO. Each block is a command that tells the computer what to do. When you connect blocks in order, you create a script, and running the script makes your program come to life.

The Scratch Interface

• Stage — the area on the right where your sprite performs.
• Sprite — a character or object you program in Scratch.
• Blocks Palette — the colored blocks on the left, organized by category.
• Scripts Area — the middle space where you drag and connect blocks.
• Green Flag — click it to run your program.
• Red Stop Button — click it to stop the program.

The Eight Main Block Categories

• Motion (dark blue) — moves and rotates the sprite on the stage.
• Looks (purple) — changes the sprite's appearance, size, or speech bubbles.
• Sound (pink) — plays sounds, music, or stops audio.
• Events (yellow) — starts a script when something happens (e.g. green flag clicked).
• Control (orange) — manages loops, waits, and if/else decisions.
• Sensing (light blue) — detects touching, keypresses, or mouse position.
• Operators (green) — does math and compares values.
• Variables (dark orange) — stores and changes numbers or text in named boxes.