Introduction to Unit Conversions and Significant Digits

Flashcards covering metric prefixes, unit equalities, uncertain digits, and rules for counting and rounding significant figures.

What mnemonic is mentioned in the lecture for remembering the metric prefixes from kilo down to milli?

"Kangaroos hopping down mountains drinking chocolate milk," where "mountains" represents the base unit of $1$.

What is the relationship between a milliliter ($\text{mL}$) and a cubic centimeter ($\text{cc}$)?

They have a $1:1$ equality, meaning $1\,\text{mL} = 1\,\text{cc}$.

What general rule relates unit size to the numerical value associated with it?

Big units get small numbers, and small units get big numbers (for example, $1,000\,\text{grams} = 1\,\text{kilogram}$).

In scientific measurements, what does the last digit of a recorded number represent?

The last digit is the uncertain or estimated digit.

How should you estimate a volume measurement when reading a graduated cylinder in the lab?

You estimate one decimal place past the marked graduation lines (for example, estimating $78.3$ when between the $78$ and $79$ lines).

What is the rule regarding non-zero digits when counting significant figures?

All non-zero digits are always significant.

Are leading zeros (zeros before the first non-zero digit) considered significant?

No, leading zeros are never significant; they only serve as place holders.

How does the presence of a decimal point affect trailing zeros in a whole number like $57,500$?

Without a decimal point, $57,500$ has $3$ significant figures because trailing zeros do not count; with a decimal point ($57,500.$), all trailing zeros count, giving it $5$ significant figures.

How many significant figures are in the measurement $53.873$?

It contains $5$ significant figures because all digits are non-zero.

What is $53.873$ rounded to $3$ significant figures?

$$53.9$$

How many significant figures are in the number $1868$?

It contains $4$ significant figures.

What is $1868$ rounded to $2$ significant figures?

$$1900$$

How many significant figures are in the number $30.04$?

It contains $4$ significant figures because the zeros are trapped between non-zero digits.

What is $30.04$ rounded to $3$ significant figures?

$$30.0$$

How many significant figures are in the number $0.00400$?

It contains $3$ significant figures because trailing zeros after a non-zero digit and a decimal point are significant.

What is $0.00400$ rounded to $1$ significant figure?

$$0.004$$

How many significant figures are in the number $40.000$?

It contains $5$ significant figures because all trailing zeros following a non-zero digit and a decimal point count.

What is $40.000$ rounded to $2$ significant figures?

$40.$ (with the decimal point included).