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Capacity

Strand: Shape and Space (Measurement)
Outcome: 5

Step 5: Follow-up on Assessment

Guiding Questions

• What conclusions can be made from assessment information?
• How effective have instructional approaches been?
• What are the next steps in instruction?

A. Addressing Gaps in Learning

To improve their estimating skills, have the students always estimate before measuring and then compare their measurements to their original estimates. As they become more familiar with the units used in capacity measurements, the students will have a better sense of estimating the capacity in the required units. Remind the students to use referents and/or chunking when estimating capacity. Have the students share their estimates and strategies for estimating. Begin by having the students estimate by comparing the capacity of two different containers. Then have them estimate the capacity of containers. Accept a range of estimates and narrow the range as the students’ estimating skills improve.

Conservation of capacity develops as students mature. Continue to provide opportunities for students to compare the amount of liquid, sand or rice in containers that have different shapes and have them communicate their thinking. Always start with two identical containers that have the same amount of liquid, sand or rice. Then pour the contents of one of the identical containers into another container that has a different shape so that the level of the liquid, sand or rice is higher or lower than the level in the original containers. Students who understand conservation of capacity will explain that the amount of liquid, sand or rice remains the same when it is poured into another container.

Students who have difficulty repeating the same unit when measuring capacity should have ample opportunities to explore using manipulatives such as 1 mL measuring spoons or 1 L milk cartons or beakers. Encourage the students to manipulate the concrete materials and explain how the unit is repeated in finding the capacity of a container.

Students who have difficulty describing the relationship between mL and L should use a variety of manipulatives, including a 250 mL milk carton, a set of measuring spoons (including sizes 1 mL, 2 mL, 5 mL, 15 mL and 25 mL) and a graduated 1000 mL beaker marked in 100 mL or 50 mL. See Step 3, Section C for a detailed description.

B. Reinforcing and Extending Learning

Students who have achieved or exceeded the outcomes will benefit from ongoing opportunities to apply and extend their learning. These activities should support students in developing a deeper understanding of the concept and should not progress to the outcomes in subsequent grades.

Consider strategies such as.

• Provide tips for parents on helping their children to estimate and find the capacities of containers. For example:
  • Ask the child to estimate the capacity of various sized containers. Have the child explain how he or she estimated the capacity by providing some explanation for the size of a millilitre and a litre.
  • Ask the child to measure the capacity of various sized containers by using measuring spoons (1 mL, 2 mL, 5 mL, 15 mL and 25 mL), a measuring cup marked in millilitres or a 1 L container, such as a milk carton. Where appropriate, have the child record the measure in millilitres and in litres.
  • Involve the child in reading the labels on liquid medication and measuring the correct amount for the age of the child.
• Provide the student with containers that all have about the same capacity, but have different shapes. Also, provide a variety of manipulatives to measure capacity, including measuring cups and spoons marked in mL, graduated beakers marked in mL and L, water, sand and rice. Have the student order the containers from the one with the least capacity to the one with the greatest capacity and explain his or her thinking.
• Pose the following problem to the student:
  Mark said that if you multiply the number of millilitres of liquid in a container by 1000, you will get the number of litres of liquid in that container. Do you agree with Mark?  Why or why not?
• Guess the Unit
  Provide the student with a variety of different measurements found in newspapers, signs or other everyday contexts. Include the context and the measure but not the units. Have the student predict what unit of measure is used in each situation and justify his or her choice to the class (Van de Walle and Lovin 2006, p. 277).