Treasure Hunt

Can you find a reliable strategy for choosing coordinates that will locate the treasure in the minimum number of guesses?
Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving
Being curious Being resourceful Being resilient Being collaborative

Problem

Treasure Hunt printable sheet

Printable grids



Can you find the hidden treasure?

The treasure has been hidden somewhere on this beach, where the grid lines intersect (cross).

Input coordinates to help find the treasure with the fewest guesses. The interactivity gives you the shortest distance you'd have to travel (along the grid lines) to reach the treasure.

Can you find a reliable strategy for choosing coordinates that will locate the treasure in the minimum number of guesses?