Lesson 19 Accuracy and errors
Lesson plan
| Piagetian Level | |||
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| 3 B Mature Formal |
Expressing error in full proportional terms. | ||
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| 3A Early Formal |
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‘the error ratio depends on how far the rounded 7 figure is from the original'. The maximum error for 2 sig. figs is 0.05. in relation to a rounded total of 7 this gives a 5% error ratio, which diminishes fo 0.5% in relation to 10’ | |
| ‘you've got to look at how big the error is compared with the total price’ | ‘the error ratio seems to depend on how far the rounding differs from the total number’ | ||
| 2B* Concrete Generalisation |
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'compared with £129.04p is almost nothing’ | |
| Infinity of numbers by continuing to subdivide by factors of 10 | ‘error is the same: it's the same cheat!’ |
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| 2B Mature concrete |
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| Increasing accuracy by reading to hundredths | |||
| Middle concrete |
Episode 1 How many numbers does this measurement cover? |
Episode 2 How big is the error? |
Episode 3 Errors in rounding |