CML: A 3-digit whole number is added to a 4-digit whole number. There is a largest possible sum and a least possible sum. What is the difference between those two sums?

CML: There are 11 children in Room A and 7 children in Room B. If _____ children move from Room A to Room B, there will be twice as many children in Room B as in Room A.

CML: Julia is making a necklace by stringing beads. She strings beads in the order: black, white, red, green and then she starts with black again going in the same order. If her necklace design begins with a black bead and ends with a red bead, then her necklace could contain exactly ____ beads.