Before we begin, let's review the decimal number system. Why does 453 represent 453? (Silly question, I know...but there is a point!)

453 = (4 x 100) + (5 x 10) + (3 x 1)

Group activity!

  • Using your cards, figure out the highest number possible you can represent
  • Count from 0 to the highest number using the cards. What pattern, if any, do you notice?
  • Is there more than one way to get any number?
  • What happens when you put a zero on the left of a binary number? What happens when you put a zero on the right of a binary number?
  • Expert challenge: Try making the numbers 1, 2, 3, and 4 in order again. Can you work out a logical and reliable method of flipping the cards to increase ANY number by 1?

An awesome Kahn Academy video!


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