Using inequality notation for errors in calculations
I can use inequality notation $$a ≤ x < b$$ to express errors in calculations.
Using inequality notation for errors in calculations
I can use inequality notation $$a ≤ x < b$$ to express errors in calculations.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- You can use the values of a and b to see what the biggest and smallest answers to a calculation could have been.
- The range of possible answers is the error interval.
Keywords
Error interval - An error interval for a number $$x$$ shows the range of possible values of $$x$$. It is written as an inequality $$a ≤ x < b$$
Common misconception
When subtracting or dividing, the largest value is found by subtracting or dividing the upper limit of a number by the upper limit of the divisor or additive inverse.
Drawing a number line to show with subtraction will help students see how to achieve an upper or lower limits of an error interval calculation. When using division, reiterating the division of number is the same as multiplying by its reciprocal.
To help you plan your year 8 maths lesson on: Using inequality notation for errors in calculations, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 8 maths lesson on: Using inequality notation for errors in calculations, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
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The assessment exit quiz will test your pupils' understanding of the key learning points.
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Explore more key stage 3 maths lessons from the Estimation and rounding unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Equipment
Licence
Starter quiz
6 Questions
Exit quiz
6 Questions
