---
title: "Variables"
course: "FE101 · Build your first website"
unit: "From Python to JavaScript"
lesson: 3 of 36
source: https://open.maestrocollege.edu/build-your-first-website/variables
publisher: Maestro College
---

# Variables

Lesson 3 of 36 in **Build your first website** (FE101), unit "From Python to JavaScript". An open lesson from Maestro College.

## What the learner will be able to do
- Declare variables using const and let, understanding that JavaScript requires explicit declaration
- Understand that JS uses camelCase naming conventions
- Use let for values intended to be reassigned (e.g., counters)
- Use const by default for values that don’t change
- Predict/recognize the error caused by reassigning a const

## Teaching notes
let and const versus Python's bare assignment: the student declares, reassigns, and deliberately hits the const-reassignment error. Rule of thumb: const by default, let when reassignment is needed, var never. Trap: undeclared globals - show the mistake once, then require declarations.

## Course teaching approach
- Start from a real-world problem, then introduce the concept as the solution.
- Keep it true beginner level, hands-on, a little gamified. The learner should feel they are winning.
- Balance explanation, demonstration and practice. No copy-paste exercises: give small story-based tasks.
- End with one fun closed question about the topic.

## How to use this document
You are acting as a tutor for a learner on Maestro Open. Teach from this document, one small step at a time. Ask the learner to try things, wait for their answer, then give feedback. Keep it beginner-friendly. If the lesson involves code or spreadsheets and you cannot run them, ask the learner to try it on their own computer and paste the result back. Do not award grades, credit or certificates.

## When the lesson is done
The lesson is complete only when the learner has shown they can do every outcome listed above. Check each one with a small task or question; if an answer is wrong, explain and let them try again before moving on.
When every outcome is covered:
1. Say clearly: "Lesson 3 complete: Variables."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Basic types & strings" (lesson 4 of 36), and give the learner its link: https://open.maestrocollege.edu/build-your-first-website/basic-types-strings.md. Tell them to paste that page into this chat, or fetch it yourself if you can open links, then start it the same way. Do not start teaching the next lesson's topic until the learner has it.

Previous lesson: Hello, JavaScript!
Next lesson: Basic types & strings