CK-12 Foundation
Arithmetic Series Sums: Adding Arithmetic Sums
Sum up the shortcuts. The interactive allows pupils to discover a shortcut in finding a partial sum of an arithmetic series. Learners use the shortcut to find other sums and to verify the process.
CK-12 Foundation
Sums of Finite Arithmetic Series: Triangular Numbers
Using a slider, scholars build triangular numbers and their associated rectangles and use the geometric display to find the pattern to determine the next triangular number. They then relate that number to the area of the rectangle to...