10001001   Binary Counter   10010001

Binary Numbers --- Introduction --- Addition --- Multiplication --- Counter --- Card game

A binary counter is a machine (like a computer) which counts in binary. A group of people can become a binary counter, and it's a good way to see how the number system works. Line up in a row, with everyone's right arm horizontal, so their hand touches the shoulder of the next person. The person on one end is the unit and has to do the most work. This is on their left-hand end of the line (but looks like our right, as we're facing them). The child on the other end does no work at all, but merely provides a shoulder! There are only two rules.
• The unit child raises or drops his arm to create each number. He must wait until other children complete this number before starting the next one.

• All other children do nothing unless their shoulder is touched by the previous child dropping his arm and touching their shoulder. Then they must change state: If the arm is down, raise it in the air. If the arm is in the air, lower it gently to touch the next child's shoulder.
Click on 'Step count' to see how it works, or 'Count' to see it counting.

 Binary Decimal Value : 0