Significant Figures and Rounding Rules

The video tutorial explains the concept of significant figures in chemistry, focusing on their importance in measurements and calculations. It introduces the rules for identifying significant figures, including handling zeros in different positions. The tutorial also covers how to perform mathematical operations like multiplication, division, addition, and subtraction while maintaining the correct number of significant figures. Rounding rules are discussed, and practical examples are provided to illustrate these concepts.

What is the primary source of numbers in chemistry?

• Theoretical calculations

• Measurements

• Historical data

• Random guesses

Which of the following is NOT considered a significant figure?

• Leading zeros

• Non-zero integers

• Captive zeros

• Trailing zeros

How many significant figures are in the number 0.002?

• One

• Two

• Three

• Four

When multiplying two numbers, how is the number of significant figures in the result determined?

• By the number with the most significant figures

• By the number with the least significant figures

• By averaging the significant figures

• By adding the significant figures

In addition and subtraction, what determines the number of decimal places in the result?

• The number with the most decimal places

• The total number of decimal places

• The average number of decimal places

• The number with the least decimal places

What is the rule for rounding if the last digit to be removed is less than five?

• Decrease the preceding digit by one

• Increase the preceding digit by one

• Keep the preceding digit the same

• Remove the preceding digit

How should the number 29876.5 be rounded to one significant figure?

• 2.99 * 10^4

• 2 * 10^4

• 3 * 10^4

• 2.9 * 10^4

In a calculation involving addition, if one number has two decimal places and another has three, how many decimal places should the result have?

• Four

• One

• Two

• Three

What is the correct way to express the result of dividing two numbers with significant figures of 5 and 3 respectively?

• With 5 significant figures

• With 3 significant figures

• With 4 significant figures

• With 2 significant figures

If the last digit to be removed in rounding is more than five, what should be done to the preceding digit?

• Remove it

• Increase it by one

• Keep it the same

• Decrease it by one