# Featured

## Two-Digit Number that Certain Sum and Difference (K-1st Graders Only)

The K-1st Grade classes explored two-digit numbers that had a sum of a certain number and a difference of a certain number. This challenge causes them to think about addition and substraction at the same time and strategically look for patterns.

## Fractals in Pascal's Triangle (5s, 1s, 2s, 4s in 1, 2, and 3 digits; multiples of 10, 2, 4, and 8)

We created beautiful fractals last week from mere triangles, quadrilaterals and inscribed circles. The children did a wonderful job of mimicking nature’s obsession with fractals. I showed them the following video of 15 plants that form spectacular fractals.

## Fractals: Self-Similarity--Inscribed Triangles, Circles, Quadrilaterals, Right Triangles

**Fractals** are self-similar objects. What does self-similarity mean? If you look carefully at a fern leaf, you will notice that every little leaf - part of the bigger one - has the same shape as the whole fern leaf. You can say that the fern leaf is self-similar.

## Constructing Regular Hexagons, Equilateral Triangles, and Derivative Works

Last week, we explored the three regular polygons that tessellate: the square, the equilateral triangle, and the regular hexagon. Creating a regular hexagon or an equilateral triangle can be done with only a compass and straight edge. This was the only way the ancient Greeks explored geometry.