Computer Science
Grade 3
20 min
Binary Bracelets: Wearable Binary
Students will create binary bracelets to represent their initials or a short word.
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Define binary as a computer language that uses only 0s and 1s.
Explain that a '1' can mean 'on' and a '0' can mean 'off'.
Convert numbers from 0 to 7 into 3-digit binary.
Read a 3-digit binary number and convert it to a number from 0 to 7.
Represent binary digits using two different colored beads.
Create a physical 'binary bracelet' that represents a number.
Decode a classmate's binary bracelet to find their secret number.
Ever wanted to send a secret message that only a computer could read? 🤫 What if you could wear that secret message on your wrist?
Today, we're going to learn the computer's secret language, called binary! It uses only two numbers, 0 and 1, to represent everything. We&#...
2
Key Concepts & Vocabulary
TermDefinitionExample
BinaryA language that uses only two symbols, 0 and 1, to represent information. It's the main language of computers.The number 5 in our normal language is written as 101 in binary.
BitA single binary digit. It is the smallest piece of information a computer can store. It's either a 0 or a 1.In the binary number 101, the '1', the '0', and the other '1' are each one bit.
DecimalThe number system we use every day, with ten digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9).The number 25 is a decimal number.
DataInformation that a computer can understand and use.Your name, your favorite color, or a number are all types of data.
RepresentationShowing information in a different way.Using a white bead for '1' and a black bead for '0...
3
Core Syntax & Patterns
The 4-2-1 Rule (Reading Binary)
4 | 2 | 1
To read a 3-bit binary number, remember that each spot has a value. The first spot is worth 4, the second is worth 2, and the third is worth 1. You only add the value if there is a '1' in that spot.
The 'Can I Fit It?' Rule (Making Binary)
Start with your number. Can you subtract 4? If yes, put a 1. If no, put a 0. Check what's left for the 2s place, and then the 1s place.
To turn a regular number into binary, start with the biggest place value (4). See if you can use it. If you can, put a '1' in that spot and use the leftover amount for the next spot. If you can't, put a '0' and move on.
4 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
You invent a new rule: a sparkly bead means 'do the last bit again'. If a bracelet is [White, Black, Sparkly], and White=1, Black=0, what code does it represent?
A.101
B.100
C.10
D.10S
Challenging
You want to make a bracelet for 'MAX'. The key is M=11, A=00, X=10. You have 4 white beads (1) and 3 black beads (0). Do you have enough beads, and if so, how many are left over?
A.Yes, you have enough, with 1 white and 1 black bead left over.
B.Yes, you have enough, with no beads left over.
C.No, you need more white beads.
D.No, you need more black beads.
Challenging
A secret code uses exactly 3 beads for every letter. What is the total number of different letters you could possibly represent with a 3-bead code?
A.3
B.6
C.9
D.8
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free