Science: Metric System and Measurement Skills
Using SI units, tools, conversions, and careful measurements
Science: Metric System and Measurement Skills
Using SI units, tools, conversions, and careful measurements
Science - Grade 6-8
- 1
Name the most common metric unit you would use to measure each quantity: length of a pencil, mass of a backpack, volume of water in a cup, and temperature of a classroom.
Think about which unit gives a number that is easy to read and compare.
The length of a pencil would usually be measured in centimeters. The mass of a backpack would usually be measured in kilograms. The volume of water in a cup would usually be measured in milliliters. The temperature of a classroom would usually be measured in degrees Celsius. - 2
Convert 4.5 kilometers to meters. Show the conversion factor you used.
4.5 kilometers is equal to 4,500 meters because 1 kilometer equals 1,000 meters, and 4.5 times 1,000 equals 4,500. - 3
Convert 750 milligrams to grams. Show your work.
Milli- means one-thousandth, so move from milligrams to grams by dividing by 1,000.
750 milligrams is equal to 0.750 grams because 1,000 milligrams equals 1 gram, so 750 divided by 1,000 equals 0.750. - 4
A graduated cylinder contains water. The bottom of the meniscus is halfway between the 36 mL and 38 mL marks. What volume should be recorded?
Always read the bottom of the curved surface of the liquid at eye level.
The volume should be recorded as 37 mL because the bottom of the meniscus is halfway between 36 mL and 38 mL. - 5
A pencil starts at the 2.0 cm mark on a ruler and ends at the 14.6 cm mark. What is the length of the pencil?
The pencil is 12.6 cm long because 14.6 cm minus 2.0 cm equals 12.6 cm. - 6
Choose the best tool for each measurement: the mass of a rock, the volume of 50 mL of water, the length of a leaf, and the temperature of pond water.
Match the tool to what it is designed to measure.
The mass of a rock should be measured with a balance. The volume of 50 mL of water should be measured with a graduated cylinder. The length of a leaf should be measured with a metric ruler. The temperature of pond water should be measured with a thermometer. - 7
A rock is placed into a graduated cylinder with 20 mL of water. The water level rises to 26 mL. The rock has a mass of 54 g. What is the volume of the rock, and what is its density?
Use water displacement for volume, then use density equals mass divided by volume.
The volume of the rock is 6 mL because 26 mL minus 20 mL equals 6 mL. Its density is 9 g/mL because 54 g divided by 6 mL equals 9 g/mL. - 8
A student records the same length as 12 cm, 12.0 cm, and 12.00 cm in three different trials using different rulers. Which measurement shows the greatest precision? Explain your answer.
The measurement 12.00 cm shows the greatest precision because it is recorded to the hundredths place, which means it uses smaller measurement intervals than 12 cm or 12.0 cm. - 9
Convert 0.35 liters to milliliters. Show your work.
To change liters to milliliters, multiply by 1,000.
0.35 liters is equal to 350 milliliters because 1 liter equals 1,000 milliliters, and 0.35 times 1,000 equals 350. - 10
A thermometer reads 25 degrees Celsius. Convert this temperature to kelvins using K = degrees Celsius + 273.15.
The temperature is 298.15 K because 25 plus 273.15 equals 298.15. - 11
Put these metric prefixes in order from largest to smallest: milli-, kilo-, centi-, base unit, micro-.
Compare each prefix to one base unit such as one meter or one gram.
The order from largest to smallest is kilo-, base unit, centi-, milli-, micro-. Kilo- is 1,000 times the base unit, while centi-, milli-, and micro- are smaller than the base unit. - 12
Choose an appropriate metric unit for each item: the length of a school hallway, the length of an ant, the volume of a water bottle, and the mass of a paper clip.
The length of a school hallway would be measured in meters. The length of an ant would be measured in millimeters. The volume of a water bottle would be measured in milliliters or liters. The mass of a paper clip would be measured in grams. - 13
A rectangular block is 8 cm long, 3 cm wide, and 2 cm tall. What is the volume of the block?
For a rectangular prism, use V = l × w × h.
The volume of the block is 48 cubic centimeters because volume equals length times width times height, and 8 times 3 times 2 equals 48. - 14
The accepted boiling point of pure water at sea level is 100 degrees Celsius. A group measures it as 96 degrees Celsius. What is the percent error?
Use percent error = absolute difference divided by accepted value times 100.
The percent error is 4 percent because the difference is 4 degrees Celsius, and 4 divided by 100 times 100 equals 4 percent. - 15
Design a simple measurement plan for tracking the growth of a bean plant for two weeks. Include the tool, unit, how often to measure, and one way to keep the data reliable.
A good plan is to measure the plant height with a metric ruler in centimeters once each day for two weeks. To keep the data reliable, the same person can measure from the soil surface to the top of the plant at the same time each day.