TES Maths: Inspect the spec - rounding
Get on top of the requirements for teaching rounding as part of the new GCSE specification with these hand-picked resources
Everyone is talking about functions and frequency trees, but what else has changed with the advent of the new specification? And what resources are available to help? Throughout this series, TES Maths aims to find out.
What does the specification say?
The expectation is that:
- All students will develop confidence and competence with the content identified by standard type
- All students will be assessed on the content identified by the standard and the underlined type; more highly attaining students will develop confidence and competence with all of this content
- Only the more highly attaining students will be assessed on the content identified by bold type. The highest attaining students will develop confidence and competence with the bold content.
N15: Round numbers and measures to an appropriate degree of accuracy (eg, to a specified number of decimal places or significant figures); use inequality notation to specify simple error intervals due to truncation or rounding
What's the same?
The core principles of rounding are exactly the same. Both foundation and higher tier students will need to be comfortable rounding numbers to the nearest whole, as well as to a specified number of decimal places or significant figures.
What has changed?
Firstly, there is the concept of truncating. This is when a number is simply chopped off after a certain amount of decimal places, instead of being rounded. This looks pretty straightforward, but I can already foresee my Year 11s getting muddled about the point at which they are supposed to check whether the next number is 5 or above, or even just disregard it entirely.
Secondly – and this is a big one – there is the use of inequality notation to specify error intervals as a result of rounding. The specification requires all students, including those at the top end of the foundation tier, to be able to work this out and this is for good reason. This topic brings together two concepts that students find notoriously difficult: error bounds and inequality notation. Students will need to be comfortable with both of these in order to crack the new GCSE content.
How can TES Maths can help?
As ever, the wonderfully talented authors of the TES Maths community have stepped up to the mark to lend a hand. Here is a selection of my favourite resources to help support the teaching of this topic:
- Introduction to rounding and estimating
Support learners as they consolidate their understanding of rounding to decimal places and significant figures with this differentiated lesson pack.
- Errors in truncation
Using calculator display screens with digits removed, students are required to use inequalities to show the maximum errors in truncating numbers.
- Bounds and error intervals
Ensure students get to grips with calculating bounds and error intervals using the engaging, superhero-themed worksheet.
- Limits of accuracy lesson
Originally created for the old specifications, this fully resourced lesson clearly demonstrates upper and lower bound measurements and is an ideal starting point from which to start looking at error intervals.
Craig Barton, TES Maths adviser
Craig is a secondary maths teacher in the North of England.
Find more resources to support the changes to the GCSE maths specification by taking a look at the rest of the series.