The upper bound for a rounded number is the smallest value that would round up to the next rounded value.

The lower bound for a rounded number is the smallest value that the number could have taken prior to being rounded.

An error interval for a number x shows the range of possible values of x.  It is written as an inequality a ≤ x < b

Upper and lower bounds

Maths

Upper and lower bounds in additive calculations

Upper and lower bounds in multiplicative calculations

Using upper and lower bounds practically

Advanced problem solving with rounding, estimation and bounds

In the prior unit, pupils 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 this unit, pupils will investigate the bounds and perform calculations to determine a best/worst case scenario.

This unit explores the impact of upper and lower bounds on additive and multiplicative calculations.

Rounding, estimation and bounds

The lower bound for a rounded number is the smallest value that the number could have taken prior to being rounded

The upper bound for a rounded number is the smallest value that would round up to the next rounded value

An error interval for a number x shows the range of possible values of x. It is written as an inequality a ≤ x < b

Rounding, estimation and bounds

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