Mental Math Computation
Multiply Mentally 84 × 25 What strategy did you use? Why did we choose 84 × 25 instead of 85 × 25?
Circle the questions that illustrate this strategy: 28 × × 25 $1.60 × × × × × × × × 25
Circle the questions that illustrate this strategy: 28 × × 25 $1.60 × × × × × × × × 25
Solve mentally and record your strategy
Teachers should examine mental math strategies to see how highest place value and compatible numbers form the basis of the strategy.
Let’s Review There is a general approach to the introduction of a strategy There is a general approach to the introduction of a strategy Question selection is very important Question selection is very important Two big ideas Two big ideas –Largest place value –Compatible numbers Flexibility Flexibility