1. Mental Math Computation

2. Multiply Mentally 84 × 25 What strategy did you use? Why did we choose 84 × 25 instead of 85 × 25?

3. Circle the questions that illustrate this strategy: 28 × 50 320 × 25 $1.60 × 25 20 × 268 7.2 × 2.5 24 × 25 280 × 26 165 × 25 0.032 × 25 25 × 25

4. Circle the questions that illustrate this strategy: 28 × 50 320 × 25 $1.60 × 25 20 × 268 7.2 × 2.5 24 × 25 280 × 26 165 × 25 0.032 × 25 25 × 25

5. Solve mentally and record your strategy 9 + 6 75 + 68 + 25 150 + 197 + 850 998 + 77

6. Teachers should examine mental math strategies to see how highest place value and compatible numbers form the basis of the strategy.

7. 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