Significant figures

• What is the purpose of stating units in measurements?

  To indicate the quantity being measured
• Why do scientists round off numbers in measurements?

  To provide a level of detail that is most useful
• What is the range of distances from the Sun to Pluto according to NASA?

  4,436,820,000,000 m to 7,315,930,000,000 m
• What is meant by significant figures in measurements?

  It refers to the digits that are important in the rounding of a number
• How would you express the number 7483 to one significant figure?

  7000
• How would you express the number 7483 to two significant figures?


  7500
• Why might an astronomer provide an approximate value for the distance from the Sun to Pluto?

  Because the distance varies over time
• What is the average distance from the Sun to Pluto calculated exactly?

  5,876,375,000,000 m
• How would you express the average distance from the Sun to Pluto to two significant figures?

  5,900,000,000,000 m
• How would you express the average distance from the Sun to Pluto to one significant figure?

  6 Tm
• What is the furthest distance from the Sun to Pluto expressed to three significant figures?

  7,320,000,000,000 m
• What is a key fact to remember when providing calculated answers?

  It is important to state units and number of significant figures
• How do you determine the number of significant figures in a decimal number?

  Ignore leading zeros and count trailing zeros
• How many significant figures does the number 4.76000 have?

  Five significant figures
• How many significant figures does the number 0.0000476 have?

  Three significant figures
• How many significant figures does the number 0.00006100 have?

  Four significant figures
• What is the value of 0.00206392 mol quoted to four significant figures?

  0.002064 mol
• What is the value of 0.00246392 amps quoted to five significant figures?

  0.0024639 A
• What are the rules for counting significant figures in decimal numbers?

  • Ignore leading zeros
  • Count trailing zeros as significant
  • Count all non-zero digits
• What is the significance of significant figures in scientific measurements?

  • Indicates precision of measurements
  • Helps communicate the accuracy of data
  • Essential for reporting calculated results
• What are the implications of using significant figures in scientific calculations?

  • Affects the reliability of results
  • Influences the interpretation of data
  • Ensures consistency in reporting measurements