Puzzle Garden
Ten coins. A small rule. A surprisingly rich arrangement problem. Drag the coins, count the lines, and look for ways that one coin can do more than one job.
Think before dragging
If ten coins were used once each, five lines of four would need twenty coin-places. The puzzle only works when coins are shared between lines.
Part 1
The tempting starting point is rows and columns. The useful question is: can one coin belong to more than one line?
Target: 5 lines of exactly 4 coins
Detected: 3 matching lines
Drag the coins until the counter reaches the target.
Part 2
This time a line with four coins is not counted. You are looking for exactly six different straight lines of three.
Target: 6 lines of exactly 3 coins
Detected: 2 matching lines
Drag the coins until the counter reaches the target.
Classroom prompts
