Challenge 161: Counter Cover-Up
Can you find the smallest amount of counters you would need to cover this square?
I have some circular counters with radius 1cm.
What is the smallest number of counters I would need to use to completely cover a square with side 2cm? Or 3cm? Or n cm?
What about a rectangle measuring n by m cm?
Remember to justify your answers.
(The counters must remain whole – I am not allowed to cut them into smaller pieces!)