Crash Course Unit Conversion and Sig Figs

How many base units are there according to the the International System of Units?

Which of the following are appropriate derived units for density?

• g/mL

• g/cm³

• kg/L

• kg/m³

In order for units to cancel they must be on ​ (a)   sides of the the division bar.

• opposite
• adjacent
• parallel
• diagonal
• the same

Why is the "does this make sense test" an important step when converting between units?

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What is an exact number?

• A number that involves estimation and approximation
• A number that is always irrational
• A number that is known with complete certainty and does not involve any estimation or approximation.
• A number that changes constantly

What are significant figures?

• Significant figures are always rounded up to the nearest whole number.
• Significant figures are only used in scientific notation.
• Significant figures are the numbers that are not important in a calculation.
• Significant figures are the digits in a number that carry meaning contributing to its precision.

What is the purpose of the exponent in scientific notation?

• To add complexity to the number
• To show how many places to move the decimal

• To make calculations easier
• To confuse students

When figuring out significant figures for addition or subtraction you use the same number of decimal places as the number with the (a)   amount of decimals.

• smallest
• largest
• equal
• random

When figuring out the number of significant figures for multiplication or division your answer should have ​ (a)   sig figs as your ​ (b)   precise measurement.

• the same
• least
• more
• equal
• fewer
• most

Why do we not report all the numbers found in our calculations?

• Those numbers are not truly known and therefore inaccurate

• The answers would be too long

• Scientists like making up rules

• Rounding to two decimal places is neater