Significant Figures Examples with Answers
Fast worked examples for the exact numbers students search: 100, 1000, 0.00450, 90.010, and common rounding questions.
How Many Significant Figures Are in 0.020?
0.020 has 2 significant figures: the 2 and the final zero after the decimal. See the digit-by-digit rule, scientific notation, and common mistakes.
How Many Significant Figures Are in 100?
100 usually has 1 significant figure when written without a decimal point. Learn why the trailing zeros are ambiguous and how to show 2 or 3 sig figs clearly.
How Many Significant Figures Are in 1000?
1000 usually has 1 significant figure when written without a decimal point. Learn why the three zeros are ambiguous and how to show 2, 3, or 4 sig figs.
How Many Significant Figures Are in 0.00450?
0.00450 has 3 significant figures: 4, 5, and the final zero. See which zeros count, why the leading zeros do not, and how to write it in scientific notation.
How Many Significant Figures Are in 0.00208?
0.00208 has 3 significant figures because the middle zero is between non-zero digits.
How Many Significant Figures Are in 90.010?
90.010 has 5 significant figures. Zeros between non-zero digits and trailing decimal zeros count.
Round to 2 Significant Figures
Learn how to round any number to 2 significant figures with clear rules, worked examples, and common mistakes for decimals, whole numbers, and scientific notation.
Round to 3 Significant Figures
Learn how to round any number to 3 significant figures with clear steps, worked examples, and common mistakes for decimals, whole numbers, and scientific notation.
Round 7982 to 2 Significant Figures
7982 rounded to 2 significant figures is 8.0e+3, which avoids ambiguous trailing zeros.
Round 0.9978 to 2 Significant Figures
0.9978 rounded to 2 significant figures is 1.0 because the next digit rounds 0.99 upward.
Round 0.83 to 1 Significant Figure
0.83 rounded to 1 significant figure is 0.8 because the next digit is less than 5.
Round 123.456 to 3 Significant Figures
123.456 rounded to 3 significant figures is 123 because the fourth significant digit is 4.
Significant Figures in Scientific Notation
In scientific notation, significant figures are counted in the coefficient, not in the power of ten.