
problem
Mystery matrix
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
The value of the circle changes in each of the following problems. Can you discover its value in each problem?
Katie had a pack of 20 cards numbered from 1 to 20. She arranged the cards into 6 unequal piles where each pile added to the same total. What was the total and how could this be done?
Amy has a box containing domino pieces but she does not think it is a complete set. Which of her domino pieces are missing?