Unit 6 · Lesson 1
6 steps. Each one is a short story and a question to answer.
The light switch in your room is either on or off. Nothing in between.
A computer works exactly like that. Its smallest unit of data is the bit, and it has only two states: 0 or 1.
Anything with two states can be a bit: an electric switch (on/off), voltage (high/low), a magnet (north/south).
All data in a computer is stored as a collection of zeros and ones.
How many states can one bit have?
Pick an answer
Bit = the smallest unit of data, with only two states: 0 or 1. A computer works exactly like that. Its smallest unit of data is the bit, and it has only two states: 0 or 1. Anything with two states can be a bit: an electric switch (on/off), voltage (high/low), a magnet (north/south).
n bits = 2 to the power n possibilities. Two bits represent 4 possibilities: 00, 01, 10 and 11. 3 bits represent 8 possibilities: from 000 up to 111.
1 byte = 8 bits. Each next unit is 1024 times the previous one. A byte is a unit of 8 bits. It represents 2 to the power 8 = 256 possibilities, from 0 to 255. Larger units each equal 1024 times the previous: kilobyte, megabyte, gigabyte, then terabyte.
Decimal = 10 digits for people. Binary = two digits (0 and 1) for the computer. That is the decimal system: it uses digits 0 to 9 and we use it every day. Like 15 and 365. The binary system uses only two digits: 0 and 1. That is what the computer uses. Like 101₂ and 111₂.
Binary to decimal: multiply each digit by its weight, then add. Write powers of 2 under the digits from the right: 1, 2, 4, 8, 16. Multiply each digit by the weight under it. A 0 vanishes, a 1 joins the sum.
Decimal to binary: divide by 2 and write the remainders from last to first. Divide the number by 2 and record the remainder: 6 ÷ 2 = 3, remainder 0. Repeat on the result until it reaches zero: 3 ÷ 2 = 1 r 1, then 1 ÷ 2 = 0 r 1.
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Every idea in the lesson with its rule, ready to screenshot and revise from.
Bit = the smallest unit of data, with only two states: 0 or 1
n bits = 2 to the power n possibilities
1 byte = 8 bits. Each next unit is 1024 times the previous one
Decimal = 10 digits for people. Binary = two digits (0 and 1) for the computer
Binary to decimal: multiply each digit by its weight, then add
Decimal to binary: divide by 2 and write the remainders from last to first
One question from every step. Answer and see your score.
Question 1 of 6
How many states can one bit have?
Unit 6
Learn what bits and bytes are, how a computer stores everything as zeros and ones, data size units from KB to TB, and converting between binary and decimal, in an animated explainer.
The same explanation as the 3D scene, written out for quick review.
Bit = the smallest unit of data, with only two states: 0 or 1. A computer works exactly like that. Its smallest unit of data is the bit, and it has only two states: 0 or 1. Anything with two states can be a bit: an electric switch (on/off), voltage (high/low), a magnet (north/south).
Page 83
n bits = 2 to the power n possibilities. Two bits represent 4 possibilities: 00, 01, 10 and 11. 3 bits represent 8 possibilities: from 000 up to 111.
Page 83, 84
1 byte = 8 bits. Each next unit is 1024 times the previous one. A byte is a unit of 8 bits. It represents 2 to the power 8 = 256 possibilities, from 0 to 255. Larger units each equal 1024 times the previous: kilobyte, megabyte, gigabyte, then terabyte.
Page 84, 85
Decimal = 10 digits for people. Binary = two digits (0 and 1) for the computer. That is the decimal system: it uses digits 0 to 9 and we use it every day. Like 15 and 365. The binary system uses only two digits: 0 and 1. That is what the computer uses. Like 101₂ and 111₂.
Page 85, 86
Binary to decimal: multiply each digit by its weight, then add. Write powers of 2 under the digits from the right: 1, 2, 4, 8, 16. Multiply each digit by the weight under it. A 0 vanishes, a 1 joins the sum.
Page 86, 87
Decimal to binary: divide by 2 and write the remainders from last to first. Divide the number by 2 and record the remainder: 6 ÷ 2 = 3, remainder 0. Repeat on the result until it reaches zero: 3 ÷ 2 = 1 r 1, then 1 ÷ 2 = 0 r 1.
Page 87, 88