Checking and securing understanding of rounding and truncating
I can estimate a value by rounding or truncating to a given degree of accuracy.
Checking and securing understanding of rounding and truncating
I can estimate a value by rounding or truncating to a given degree of accuracy.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The first significant figure is the first non-zero digit to have place value.
- Truncation does not consider the digits that follow in the value.
- The loss of accuracy through rounding is not always bad.
Keywords
Round - Rounding means to change a number into another number that is approximately the same value but is easier to work with.
Degree of accuracy - A degree of accuracy shows how precise a number or measurement is. E.g to the nearest cm, nearest 10, 1 s.f., etc.
Significant figures - Significant figures are the digits in a number that contribute to the accuracy of the number. The first significant figure is the first non-zero digit.
Truncation - Truncation is when we simplifying a number by 'cutting off' one or more of the digits and replacing them with zeros if necessary to preserve place value.
Common misconception
When truncating, pupils are tempted to round. Also, when truncating, they cut off the number without thinking about the magnitude.
The use of the place value table shows the magnitude of the number, thus preserving their place value when truncating.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
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40
290
300
1400
1390
Exit quiz
6 Questions
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0.012
0.010
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