Computers store everything — numbers, words, pictures and music — using just two states: on and off, written as 1 and 0. This is binary. With a row of light bulbs, children discover how on and off can make any number.
What your child will learn
- Know that computers use binary: 1 for on and 0 for off
- Read numbers made from light bulbs worth 8, 4, 2 and 1
- Show a number using bulbs
- Read short binary numbers such as 101
Bulbs worth 4, 2 and 1
Line up three bulbs worth 4, 2 and 1. Switch on the 4 and the 1 and you have 4 + 1 = 5, written in binary as 101. Three bulbs can make every number from 0 to 7; add an 8 bulb and you can reach 15.
Each place is worth double the one to its right — the same idea as tens and hundreds, but with twos.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. Each bulb that is on is worth 4, 2, 1 from left to right. What number do the bulbs show?
- 7
- 6
- 1
- 2
Show answer
Answer: 6. The bulbs that are on are worth 4 + 2 = 6. Bulbs that are off count for nothing.
2. Each bulb that is on is worth 4, 2, 1 from left to right. What number do the bulbs show?
Show answer
Answer: 3. The bulbs that are on are worth 2 + 1 = 3. Bulbs that are off count for nothing.
3. Each bulb that is on is worth 4, 2, 1 from left to right. What number do the bulbs show?
Show answer
Answer: 2. Only the 2 bulb is on, so the number is 2. Bulbs that are off count for nothing.
Tips for grown-ups
- Use cards or cups (face up = 1, face down = 0) to make binary numbers.
- Count from 0 to 7 in binary together: 000, 001, 010, 011…