©G Dear 2008 – Not to be sold/Free to use Units of Measurement General Mathematics Preliminary Significant Figures Stage 6 - Year 11 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use

Significant Figures (1/3) Accuracy is limited by the instrument used in the measurement. Significant figures represent the practical degree of accuracy. We DON’T need to know the distance of the Sun from the earth to the nearest kilometre. 3 significant figures is enough. 146 000 000 km.

Significant Figures (2/3) Significant figures are the given number of non-zero numbers from the left. Zeros at the beginning Zeros at the end may be significant. are not significant. 0.00 3 406 000 Zeros in the middle are significant.

Significant Figures (3/3) Write the following numbers to the significant figures shown in [ ]. 1. 2 434 333 [2] 2 400 000 2. 0.000 253 [1] 0.000 3 3. 4.546 7 [3] 4.55 4. 39 537 [2] 40 000 5. 0.099 253 [3] 0.099 3