91Ó°ÊÓ

Based on the following rules, we determine which digits in a number are significant:

• All non-zero digits are significant.
• Zeros present in between non-zero digits are significant.
• Zeros which come after the decimal point are significant (trailing zeroes).
• Zeros which come before the decimal and any non-zero number are insignificant (leading zeroes).

a) 53cm: It has 2 non-zero digits and both of them are significant.

b) When we divide or multiply two numbers, we have to round the result to the same of the digits as the number with the least number of significant figures. But 2.05 × 10⁸ m has 3 significant figures since each of the numbers also has 3 significant figures each.

c) 86,002 J : It has 3 non-zero digits and 2 zeros between the non-zero digits, therefore we have a total of 5 significant figures here.

d) 9.740 × 10⁴ m/s:Number of significant figures here is 4, as the zero after a decimal point is considered significant.

e) 10.0613 m³ All the digits are significant according to the rules given above.

f) 0.17 g/mL: The zero is insignificant as it is a leading zero.

g) 0.88400 s : Total significant figures = 5 since the leading zero is insignificant but the trailing zeroes are significant.