standard_description: Develop a probability distribution for a random variable defined for a sample space in which probabilities are assigned empirically; find the expected value. For example, find a current data distribution on the number of TV sets per household in the United States, and calculate the expected number of sets per household. How many TV sets would you expect to find in 100 randomly selected households?
problem_activity: Stage 2: Subtract within 10
Required Preparation
Materials to Gather
Number cards 0–10
Materials to Copy
Blackline Masters
Check It Off Stage 2 Recording Sheet

Narrative
Students take turns picking two number cards (0–10) to make and find the value of a subtraction expression. Students check off the number that represents the value of the difference (0–10) and then write the subtraction expression on the recording sheet.
Variation:
Students can choose whether to add or subtract after picking two number cards.


aligns: no