# Featured

## Hexadecimal Number System Converted to Decimal

We spent several weeks studying the Mayan vegidecimal (Base 20) number system with 20 symbols, then the binary (Base 2) system used by computers with only 1s and 0s, and last week, used the binary system to look at exponential decay using 1/2, 1/4, 1/8 and so on.

## Super Blood Blue Moon

The Mathletes were in for a rare treat on Wednesday, January 31, 2018 that hasn't been witnessed since 1866, 152 years. We spent the first part of class discussing this astronomical phenomenon.

## Folding Paper in Half - Exponential Decay - Fraction Denominators Resemble Binary Numbers

I had the Mathletes folding a paper plate in half. They were only able to do this four times: 1/2, 1/4, 1/8, 1/16. The children noticed that each time the paper got a half smaller, the denominator of the fraction doubled like the binary numbers.

## Converting Base 2 Binary Numbers to Base 10 Decimal

Over the last few weeks we have been exploring Base number systems different from our own decimal Base 10, which we take for granted. Our system (which uses 10 symbols) is much less efficient than the ancient Mayan vigesimal Base 20 system that uses only 3 symbols (a dot for 1, a stick for 5, and a shell for 0).

## Mayan Numbers: Base 20 Number System vs. Base 10

The Maya number system is very different from the system you use daily—the Maya used only three symbols to represent all numbers! They used a dot to represent 1, a line to represent 5, and a shell to