Unit Conversion/Significant Figures (Module 3) Flashcards
What do measurements often result in?
Approximate numbers
What do significant figures indicate?
the degree of accuracy of the measurement
What determines the amount of significant digits?
the precision of the instruments used
What does a significant digit include?
the digit that determines the degree of precision of the number and all digits to the left of it, except for zeros used to place the decimal.
What are examples of significant digits?
- All digits from 1 to 9 are significant.
- All zeros between significant digits are
significant. - Final zeros of decimal numbers are significant.
What are exact numbers?
- Exact numbers have an infinite number of significant figures.
- Exact numbers are counting up how many of something are present, they are not measurements made with instruments.
What is an example of exact numbers?
- The number of people in a room
- Defined numbers, such as 1 foot = 12 inches
When +, -, what are the rules>
- answer cannot be more precise than the lease precise measurement
-answer can’t have more decimals than the numbers with the least decimals
-round answer to the least number of places to the decimal point of any number in the problem
What is the rule for X, /
- Answer can’t have more sig figs than the one with the fewest
- round answer to the number with the least amount of sig figs
What does a conversion factor do?
A conversion factor changes something to a different version or form without changing the actual quantity.
What is SI?
International System
What are the unit conversion steps?
- Step 1: Write down the given value on the left side and the unknown value on
the right side. - Step 2: Find the conversion factor that gives a ratio between the known value and the unknown value.
- Step 3: Write the conversion factor as a fraction with the unit you want to convert to on top and the unit you want to convert from on bottom.
- Step 4: Calculate by multiplying the conversion factor.
