11. What number should be put in the ?
12. Determine the value of 4 tens + 2 ones + 3 tens?
13. Roy wants to divide 11 marbles into to 2 groups such that Group 1 has an odd number of marbles while Group 2 has an even number of marbles. What is greatest number of marbles that can be put in Group 1 if no group should be empty?
14. Today is August 15, 2020. What is the date exactly 1 week ago?
15. At least how many small cubes are added to make the figure below a bigger cube?