Some of the fourth graders in Mr. Speno's class and in Anne's class have been learning to work in base-3 by playing games and doing computation. Here's what one student wrote about base-3 and how it compares to the number system that we use, base-10:
There are similarities and differences between the base-10 and the base-3 number systems. Both base-3 and base-10 use the digits 0 through 2. Digits are symbols that represent an amount. In math, they use similar bundling and place value. In both bases, the order of the digits matters. However, there are differences too. Base-10 uses digits 3-9. Base-3 does not. Base-10 bundles in groups of 10. Base-3 bundles in groups of 3. We have ones, tens, hundreds, etc but base-3 has ones, threes, nines, twenty sevens, etc. Base three seems unusual but it's not that different from what we usually use.
