Topic 1: Rounding and Approximations

Vocabulary flashcards covering core definitions, rounding rules, significant figures, and estimation from Topic 1 notes.

Rule for Rounding Up

The procedure applied when a digit is $5$ or greater.

Rule for Rounding Down

The procedure applied when a digit is $4$ or less.

First Significant Figure

The first non-zero digit when reading a number.

Zeros After the First Significant Figure

Digits that follow the first non-zero digit and are considered significant.

Rough Estimate

A calculation method where, unless told otherwise, each number is rounded correct to $1\text{ s.f.}$

Methods of Rounding Numbers

Rounding to the nearest whole number (units, tens, hundreds, etc.), decimal places ($1\text{ d.p.}$, $2\text{ d.p.}$, etc.), or significant figures.