Tie for Two:
B and C use the same numbers
B and C are the same equation
A and B show regrouping/ungrouping
C and D don’t use regrouping
A and B use digits to represent whole numbers

Thread for Three:
A, C, & D are all addition problems
A, B, and D don’t use a number line
A, B, and D are stacked vertically
B, C, & D all have two thousands numbers in the equation (or all have one “not-thousands” number)
A, B, and D all start in the ones place and work their way to the left

Fit for Four:
All have numbers in the thousands
All have correct solutions