Binary Numbers for Kids, Explained Simply with Cards
Five point cards explain binary place value, how to write 9, and the range from 0 to 31.
Read articleBinary and addition
Binary Numbers and How Computers Add
These articles start with a row of cards. See how 0 and 1 show numbers and how far a given number of bits can reach, then follow step by step how a machine adds, and finally check yourself with practice problems and paper cards. Each article stands on its own.
Showing numbers with 0 and 1
Use flip cards to understand place value, try the card activity, and learn how many states a number of bits has and how large it can go.
Binary Cards Activity: A Binary Counting Game
Use five handmade cards or the cards on the website to build five target numbers, with an answer table and common mix-ups.
Read articleWhy 8 Bits Max Out at 255, Not 256
How bit count, number of states and maximum value relate, and why 8 bits top out at 255.
Read articleAddition and adding machines
Start with the carry rules, then meet the half adder, the full adder, the jobs of AND and XOR, and how a carry moves from column to column.
Binary Addition with Carry, Step by Step
The four basic rules of binary addition, where carries come from, and 3+1 worked column by column.
Read articleHalf Adder vs Full Adder: Carry In Explained
Compare the inputs, outputs and truth tables of half and full adders, and see what carry in means.
Read articleHow Do Computers Add Numbers?
A simplified whole-number adding model showing how computers add using 0s, 1s and logic units.
Read articleHalf Adder: Truth Table and What Each Input Does
The four half adder inputs row by row, what XOR and AND each do, and how to check the result.
Read articleFull Adder: Carry In, Carry Out and the Two Half Adders
How a full adder handles A, B and Cin with two half adders and an OR, with every intermediate value for all 8 rows.
Read articleWhy Addition Uses Both AND and XOR
In one-bit addition, XOR and AND each answer one question, and OR can't replace them.
Read articleRipple Carry: Tracing 7+1 Column by Column
Follow every carry in 7+1 column by column, from where it starts to where it stops.
Read articlePractice and hands-on materials
Grouped binary addition problems with answers, plus binary cards you can print and cut out.
Binary Addition Practice with Answers
12 grouped binary addition problems: work them first, then check the answer, the decimal check and the carry notes.
Read articlePrintable Binary Cards: Download, Cut Out and Start Flipping
A two-page A4 PDF: five point cards on one page, steps and target answers on the other. Print, cut and play.
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