doing math vs. understanding math david “coach g” ginsburg [email protected]
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Electrolysis
Doing Math vs. Understanding MathDavid Coach G [email protected] would you solve this problem? A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
2Would you use this approach? A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
$124.00 x .35 = $43.40$124.00 - $43.40 = $80.60
[email protected] approach? A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
100% - 35% = 65% $124.00 x .65 = $80.60
[email protected] would you do something like this?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
65% = 50% + 10% + 5%$124.00 x 50% = $62.00$124.00 x 10% = $12.40 $124.00 x 5% = $ 6.20 Sale price = $80.60
[email protected] one approach better than others? Why?Procedural FluencyConceptual [email protected] Fluency > AccuracyProcedural fluency is the ability to apply procedures accurately, efficiently, and flexibly
NCTM Position Paper
[email protected] #1: Efficient? Flexible?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
$124.00 x .35 = $43.40$124.00 - $43.40 = $80.60
[email protected] #2: Efficient? Flexible? A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
100% - 35% = 65% $124.00 x .65 = $80.60
[email protected] #3: Efficient? Flexible?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
65% = 50% + 10% + 5%$124.00 x 50% = $62.00$124.00 x 10% = $12.40 $124.00 x 5% = $ 6.20 Sale price = $80.60
[email protected] #1: Conceptual understanding?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
$124.00 x .35 = $43.40$124.00 - $43.40 = $80.60
[email protected] #2: Conceptual understanding?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
100% - 35% = 65% $124.00 x .65 = $80.60
[email protected] #3: Conceptual understanding?A pair of shoes that cost $124 was on sale for 35% off. What is the sale price?
65% = 50% + 10% + 5%$124.00 x 50% = $62.00$124.00 x 10% = $12.40 $124.00 x 5% = $ 6.20 Sale price = $80.60
[email protected] Fluency and Conceptual Understanding5 Supporting Practices for Your Classroom
[email protected]. A Purpose for Every [email protected]
152. Pencils Down, Minds On
[email protected]. Multiple Solution [email protected]
174. Gradual Rapid Release of [email protected]
Work the crap out of every problem185. Assist Less, Assess [email protected]
19The Procedural Fluency and Conceptual Understanding ConnectionJoin me tomorrow for pencils down, minds on math!
12:30 - Room 303