Chapter 2 - Measurements Flashcards
What is an uncertain number?
the estimated number that can vary
What do you do when making a measurement?
record all the certain numbers and the first uncertain number
A measurement always has some degree of
uncertainty
What are significant figures?
the certain numbers and the first uncertain number recorded in a measurement
What are the rules for counting significant figures for nonzero integers?
They ALWAYS count
Do leading zeros count in significant figures?
NEVER
What do you do with captive zeros when counting for significant figures?
they ALWAYS count
When do trailing zeros count in significant figures?
When the number is written with a decimal point
If a number to be rounded off is trailed by a 5, what do you do?
you add one only if the preceding number is odd; otherwise, leave the number alone
In a series of calculations, what should one do with extra digits?
carry them through the calculations then round off at the final result
For multiplication and division, the number of significant figures in the result should be?
the smallest number of significant figures in the operation
For addition and subtraction, the limiting term (# of sig. figs.) is the one with…
the smallest # of decimal places
What are exact numbers?
numbers obtained without measuring
Scientific notation always represents the correct number of what?
significant figures
