Arithmetic
Arithmetic for entrance exams, where the method was built. Judgment flowcharts, step-by-step explanations and animations are generated for each problem.
Case studies (4)
MaterialEntrance-exam arithmetic (moving figures)
How far can a dog on a rope move around its kennel?
A dog is tied by a 4 m rope to the corner of a 2 m by 4 m kennel. Where the rope catches on a corner, the centre and radius of the arc change. Noticing that switch is the judgment this problem turns on. Four steps, each with a figure and the equation.
MaterialEntrance-exam arithmetic (solids of revolution)
The volume of a solid made by spinning a right triangle
A right triangle with sides 5, 12 and 13 cm is rotated once around a line. What solid appears, where is its base, and which length is its height? A one-minute animation in which the figure builds up in the order of the judgments.
MaterialEntrance-exam arithmetic (solids)
The volume of a triangular pyramid from its net
Fold a 12 cm square into a triangular pyramid and find its volume. Solved in three steps, starting from spotting which edges become perpendicular when folded.
MaterialEntrance-exam arithmetic (plane figures)
Two angles in a figure made of set squares
Two set squares overlap; find the two marked angles. Solved by first writing in the fixed angles of the set squares, then using the angle sum of a triangle.
An explanation animation
The figure moves and shows the flow of judgment in order. About a minute per problem; pause and go back at will. The article for this problem is in preparation.
Example: sum of an arithmetic sequence (57 s, 13 scenes). Press "Play". Open in a new window ›