Understanding Significant Figures and Measurements

What do lumens, feet, kilograms, and volts represent?

• Different types of energy

• Different ways to measure things

• Different kinds of matter

• Different types of forces

What is the International Prototype Kilogram (IPK)?

• A special type of scale used to weigh very light objects.

• A specific metal object that helps define the exact weight of one kilogram.

• A unit of measurement for how long something is.

• A battery that provides 9 volts of power.

How many basic units are part of the International System of Units (SI)?

• Three

• Five

• Seven

• Ten

Why is using Earth's rotation to define a "second" becoming less accurate?

• The Earth is spinning faster.

• The Earth's rotation is gradually slowing down.

• The Earth is moving closer to the sun.

• The Earth's size is changing.

What is the main difference between an exact number and a measured number?

• Exact numbers are always whole numbers, while measured numbers always have decimals.

• Exact numbers are known perfectly, while measured numbers have some uncertainty.

• Exact numbers are used in math, and measured numbers are used in science.

• Exact numbers are smaller than measured numbers.

Why is it important to know the precision of a measured number?

• To make the number look longer.

• To ensure calculations are accurate and avoid mistakes.

• To make it easier to remember the number.

• To show off how good your measuring tool is.

How does scientific notation help when dealing with significant figures?

• It makes numbers shorter.

• It clearly shows which zeros are important (significant).

• It helps you add numbers faster.

• It only works for very large numbers.

When adding or subtracting numbers, how do you decide how many decimal places your answer should have?

• The answer should have the same number of decimal places as the number with the most decimal places.

• The answer should have the same number of decimal places as the number with the fewest decimal places.

• The answer should have the same total number of digits as the number with the most digits.

• The answer should always have two decimal places.