standard_description: Determine the unknown whole number in an addition or subtraction equation relating to three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = �� – 3, 6 + 6 = ��.
problem_activity: Problem 7
Pre-unit
The line plot shows the lengths of some toothpicks in inches.
[IMG]
How many measurements are there?
What is the difference between the longest and shortest toothpicks?


aligns: no