Express the following numbers to four significant figures : (i) 5.607892 (ii) 32.392800 (iii) 1.78986 xx 10^3 (iv) 0.007837.

Express the following numbers to four significant figures : (i) 5.607

1.	Express the following numbers to four significant figures : (i) 5.607892 (ii) 32.392800 (iii) 1.78986 xx 10^3 (iv) 0.007837.
Answer» Solution :(i) In the NUMBER 5.607892, the DIGIT to be RETAINED is 7. It is followed by digit 8 which is greater than 5. Hence, the rounded off number is 5.608. (ii) In the number 32.392800, the digit to be retained is 9. This is followed by 2 which is less than 5. Hence, 9 is left unchanged and the rounded off number containing four significant FIGURES is 32.39. (iii) In the number `1.78986 xx 10^3`, the digit to be retained is 9. This is followed by 8 which is greater than 5. Hence, the digit 9 is increased by one and the number containing four significant figures is `1.790 xx 10^3`. (IV) The number 0.007837 already contains four significant figures. In exponential notation, this can be written as `7.837 xx 10^(-3)`. This still contains four significant figures.