Here’s a fun, hands-on activity that uses paper “light bulbs” to introduce binary (bi- = 2), the number system with only two numbers, 0 and 1. Aimed at upper elementary, I’ve also taught this binary lesson to students as young as first grade by slowing the pace. Binary is the language used by computers—they run on electricity, which can only be on or off (O or 1).
Students will contrast the place value for the decimal system (1, 10, 100, etc.) with the binary place value (1, 2, 4, etc.) Directi