Discrete or Continuous? Variable Sorting Worksheet

Name:

Date:

Part 1: What do the words mean?

Discrete = counted. The values are usually whole numbers, such as the number of books.

Continuous = measured. The value can be anywhere within a range, including decimals, such as height or distance.

Word bank: counted · measured · whole numbers · decimals · units · precision

Success criteria: I can classify a numerical variable and justify my choice using the context.

Reading support: Ask for the six dataset snippets to be read aloud. Highlight words showing a count, measurement, unit or recording precision.

Part 2: Variable Sort Table

For each variable, write discrete or continuous. Then explain how you know.

Variable

1. Books borrowed from the school library in one week

2. Height of a seedling, measured in centimetres

3. Time for a swimmer to finish a race, recorded to the nearest second

4. Money spent at the school fair, recorded to the nearest cent

5. Number of students absent from class

6. Distance run during a fitness challenge, measured in metres

7. Number of complete laps run around the field

8. Air temperature at 9:00 am, measured in °C

9. Number of text messages received in one day

10. Volume of water in a bottle, measured in millilitres

Discrete or Continuous

How do you know?

Sentence starters: “I chose discrete because it is counted in whole numbers.” “I chose continuous because it is measured and could include decimals.”

Teacher Answer Key and Challenge

Answers:

1. Discrete — books are counted and whole numbers are meaningful.

2. Continuous — height is measured and can include decimals.

3. Continuous — time is measured; recording to seconds is only the measurement precision.

4. Discrete as recorded — cents are counted in whole cent units. The underlying amount of money may be continuous.

5. Discrete — students absent are counted.

6. Continuous — distance is measured and can include decimals.

7. Discrete — complete laps are counted in whole numbers.

8. Continuous — temperature is measured in °C and can have decimal values.

9. Discrete — messages are counted.

10. Continuous — volume is measured and can include decimals.

Extension: A race time is recorded only in whole minutes. Is the time itself discrete or continuous? Explain the difference between the variable and its recording precision.

Curriculum links: NZ-TMA-MATHEMATIC-Y7-8-statistics-107-DOC127, NZ-TMA-MATHEMATIC-Y7-8-statistics-109-DOC127, NZ-TMA-MATHEMATIC-Y7-8-statistics-110-DOC127.