Securing understanding of rounding
Lesson details
Learning outcome
I can recognise when values have been rounded and state sensible suggestions of what the unrounded value could have been.
Key learning points
- When a number has been rounded you can make conjectures about what the unrounded number could have been.
- Rounding can be very useful in real life contexts particularly measure.
- When working in some real life contexts you are often working to a certain degree of accuracy.
- Numbers in different contexts will be rounded to a different degree of accuracy (e.g. distance when walking or flying).
Keywords
Conjecture - A (mathematical) statement that is thought to be true but has not been proved yet.
Degree of accuracy - A degree of accuracy shows how precise a number or measurement is. E.g. to the nearest cm, nearest 10, 1 d.p., etc.
Common misconception
The assumption that if a number ends in 2 zeros it must have been rounded to the nearest hundred.
Choose examples that round to the same value when rounded to the nearest ten and hundred in this case. E.g. 398, rounds to 400 to the nearest ten and 400 to the nearest hundred.
Teacher tip
Get pupils to come up with their own 'what number am I?' problems. Emphasising that their clues must lead to a unique number. Pupils can then challenge each other to solve their problems or a pupil can present theirs to the whole class.
Licence
except where otherwise stated. See Oak's terms & conditions (Collection 2).Lesson video
Loading...
Prior knowledge starter quiz
6 Questions
Q1.Rounding means to change a number into another number that is approximately the same value, but is to work with.
Q2.27 345 rounded to the nearest thousand is .
Q3.Lucas buys a t-shirt costing £22.25. What is the cost of the t-shirt to the nearest pound?
Q4.Round 305.7298 to 1 decimal place.
Q5.Round 0.06921 to 2 decimal places.
Q6.Round 12.89528 to 2 decimal places.
Assessment exit quiz
6 Questions
Q1.Degree of accuracy shows how a rounded number or measurement is.
Q2.Select the numbers that do not round to 14 000 when rounded to the nearest thousand.
Q3.54 528 is 54 500 to the nearest ...
Q4.Jacob estimates how many pieces of pasta are in a bowl of pasta. Which of the following is the most appropriate degree of accuracy in this situation?
Q5.A charity is sending thank you cards to 160 people who have made donations. Stamps come in books of 12. How many books of stamps do they need to buy?
Q6.Izzy buys a large bag of 75 chocolate bars. She puts them into boxes of 4 to sell for charity. How many boxes will Izzy have to sell?
To help you plan your 8 maths lesson on: Securing understanding of rounding, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 8 maths lesson on: Securing understanding of rounding, 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.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
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.