Lesson objective: Apply place value subtraction strategies to solve problems using multiples of ten.
This lesson provides an opportunity for students to apply their knowledge and understanding of place value subtraction strategies a mathematical situation. Students are asked to check if Kareem correctly earned Bingo by seeing if the answers shaded on his gameboard match the equations read to the class.
Key Concept students will use:
 We can use our understanding of place value to add and subtract multiples of ten.
Skills students will use:
 knowledge of place value understanding (Grade 1, Unit 8).
 strategies for adding multiples of ten with representations (Grade 1, Unit 11).
Students engage in Mathematical Practice 6 (Attend to Precision) as they use a strategy to solve equations and check if Kareem has the correct answers on his Bingo board.

MP.6: Students attend to precision as they use a strategy to solve an equation and check to see if Kareem has that answer on his board.
Key vocabulary:
 base ten blocks
 known facts
 open number line
 place value
 subtract
 tens
Special materials needed:
 base ten blocks (optional)
 open number line (optional)