2.1 Approximations and Errors

• estimate measurement of different quantities in real life situations
• calculate errors arising from estimations and measurement
• compute percentage error from estimation and measurements
• apply errors and approximations to real life situations
• reflect on the effect of errors in estimates and measurements of quantities

“How are estimates and measurements used in real life?”

“Why is it important to minimize errors when measuring?”

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1. Estimating quantities
   40 min · 1 practice tasks · quiz
   Make sensible estimates of length, mass and capacity, and round numbers when an exact value is not needed.
2. Decimal places and significant figures
   40 min · 1 practice tasks · quiz
   Round numbers to a given number of decimal places and significant figures.
3. Estimating and measuring quantities
   40 min · 1 practice tasks · quiz
   Estimate and then measure length, mass and volume with suitable instruments.
4. Accuracy and the smallest unit
   40 min · 1 practice tasks · quiz
   Use the smallest unit of an instrument to state how accurate a measurement is.
5. Absolute and relative error
   40 min · 1 practice tasks · quiz
   Find the absolute error and the relative error of a measurement.
6. Percentage error
   40 min · 1 practice tasks · quiz
   Express the relative error as a percentage and judge the quality of a measurement.
7. Errors in calculations
   40 min · 1 practice tasks · quiz
   Find the largest and smallest possible result when measured values are added.
8. Applications and effects of errors
   40 min · 1 practice tasks · quiz
   Apply approximations and errors to real situations and reflect on their effects.