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If you read in the Saturday sports section of the paper that the attendance at a football match was exactly 43,786 and a friend asked you about the attendance at school on Monday, you would probably say about 44,000. In this case you are giving an approximate answer to 2 S.f. Significant Figures It is often necessary/convenient/sensible to give approximations to real life situations or as answers to certain calculations.

Significant Figures (Rounding) Numbers can be rounded to 1,2, 3 or more significant figures. We count the number of figures from the first non-zero digit. Rounding to 1 s.f 5 or bigger ? or bigger ? or bigger ? 0.04 NoYes No First non-zero digit.

Rounding to 1 s.f or bigger ? or bigger ? Yes First non-zero digit. Significant Figures (Rounding)

or bigger ? or bigger ? Yes First non-zero digit. Significant Figures (Rounding) Rounding to 2 s.f

or bigger ? or bigger ? Yes No First non-zero digit. Significant Figures (Rounding) Rounding to 2 s.f

or bigger ? or bigger ? Yes First non-zero digit. Significant Figures (Rounding) Rounding to 3 s.f

or bigger ? or bigger ? No Yes First non-zero digit. Significant Figures (Rounding) Rounding to 4 s.f

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number. Rounding whole numbers to 1 s.f or bigger ? No or bigger ? No or bigger ? Yes

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number Rounding whole numbers to 1 s.f or bigger ? 200 No or bigger ? 600 Yes or bigger ? 80 Yes

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number Rounding whole numbers to 2 s.f or bigger ? Yes or bigger ? Yes or bigger ? No

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number Rounding whole numbers to 2 s.f or bigger ? 240 No or bigger ? 290 Yes or bigger ? 760 Yes

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number Rounding whole numbers to 3 s.f or bigger ? No or bigger ? Yes or bigger ? Yes

Significant Figures (Rounding) When we approximate whole numbers we may need to insert zeros as required in order to maintain the size of the number Rounding whole numbers to 4 s.f or bigger ? No or bigger ? Yes or bigger ? Yes

The following number could be the population of a country at a particular instant in time.Write this number to 1, 2, 3, 4, 5, 6 and 7 significant figures