How many moves does it take to swap over some red and blue frogs? Do you have a method?
In how many ways can you fit all three pieces together to make shapes with line symmetry?
Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?
Are these games fair? How can you tell?
Find the frequency distribution for ordinary English, and use it to help you crack the code.
If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?
How many pairs of numbers can you find that add up to a multiple of 11? Do you notice anything interesting about your results?
Each clue in this Sudoku is the product of the two numbers in adjacent cells.
A country has decided to have just two different coins. Which totals can be made? Is there a largest total that cannot be made? How do you know?
How many ways can you find to put in operation signs (+, −, ×, ÷) to make 100?
