A (mathematical) statement that is thought to be true but has not been proved yet.

A degree of accuracy shows how precise a number or measurement is.  E.g. to the nearest cm, nearest 10, 1 d.p., etc.

Securing understanding of rounding

Maths

Checking understanding of rounding

Rounding to three decimal places

Rounding to any number of decimal places

Rounding integers to one significant figure

Rounding integers to significant figures

Rounding decimals to significant figures

Degrees of accuracy

Estimating numerical calculations

Checking by estimating

Truncating

Overestimating vs underestimating

Rounding errors

Inequality notation to express error

Using inequality notation for errors in calculations

Problem solving with estimation and rounding

In this unit, pupils have learnt how to round to a given number of decimal places or significant figures and explored the effect of using rounded numbers for calculations. In the future unit, pupils will investigate the bounds and perform calculations to determine a best/worst case scenario.

The prior unit on place value allowed pupils to develop the skills needed to estimate and round values. By understanding the value of each digit, pupils can determine what other values are close to the original value. This unit continues the exploration of the infinite nature of sets of numbers.

This unit helps pupils understand rounding to different decimal places, and significant figures. Pupils will also learn how to truncate numbers and understand the contexts in which these skills are useful. The unit ends will an exploration of rounding and inequality errors.

Estimation and rounding

Degree of accuracy shows how {{ }} a rounded number or measurement is.

Select the numbers that do not round to 14 000 when rounded to the nearest thousand.

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?

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?

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?

Rounding means to change a number into another number that is approximately the same value, but is {{ }} to work with.

27 345 rounded to the nearest thousand is {{ }}.

Lucas buys a t-shirt costing £22.25.  What is the cost of the t-shirt to the nearest pound?

Securing understanding of rounding

Lesson outcome