A Gentle First Triangle
With eight rows, the numbers stay small: the largest, 35, sits in the middle of the last row. Each blank asks for one addition of two numbers below 40, which suits children from about second grade.
Coloring the Odd Cells
After the blanks, the child colors every odd number. Eight rows make a complete pattern: three triangles of odd cells around an empty center, each made of three smaller ones, 27 colored cells in all.
Why Twelve Sheets?
The numbers of the triangle never change, so each sheet differs by its blanks. Twelve sheets give enough practice to fill the triangle with confidence, and the workbook keeps them together.