Year 7 Science · Unit 4 · Lesson 5
Foundation Worksheet
Learning Goals
1. Name the five senses. Then give one example of a sense being fooled, or being unable to give an exact number.
Match each rough guess to a better instrument
Write the letter of the instrument that would turn each guess into an exact number. Each letter is used once. The letters are not in the same order as the guesses.
| Rough guess using the senses | Letter | Instrument and unit |
|---|---|---|
| “The bath water feels warm.” | A. A tape measure, reading in centimetres | |
| “The desk looks about a metre long.” | B. A measuring cylinder, reading in millilitres | |
| “This schoolbag feels heavier than that one.” | C. A thermometer, reading in degrees Celsius | |
| “That felt like about a minute.” | D. A balance, reading in grams or kilograms | |
| “There is about a glass of juice left.” | E. A stopwatch, reading in seconds |
Fill the gap
Choose the correct word from the word bank. Each word is used at most once. Two words are not needed: cross them out.
What you directly notice with your senses, or measure with an instrument, is an . A conclusion you work out from it, using what you already know, is an , and it could still be . A statement about what will happen next is a . The most useful ones in science are , because an experiment or a measurement can check them.
Observation or inference? Sort it
You walk through the school picnic area after lunch. Write each statement in the correct box. The boxes do not hold the same number of items.
Observation (noticed or measured)
Inference (worked out)
Read the data: eyes versus a tape measure
Scenario
A group guessed the length of four objects just by looking. Then they measured each one with a tape measure.
| Object | Guess by eye (cm) | Tape measure (cm) | How far off (cm) |
|---|---|---|---|
| Pencil | 15 | 17 | 2 |
| Desk | 100 | 120 | |
| Door (height) | 180 | 204 | |
| Library book | 30 | 28 | 2 |
Source: sample class results.
2. Fill in the two empty cells in Table 1. Which guess was furthest from the measured length?
3. Use Table 1 to explain why scientists measure length with an instrument instead of judging it by eye.
4. On Monday morning your class finds the pot plant by the window drooping, and its soil is dry. Write (a) one observation, (b) one inference, (c) a second inference that could also explain the drooping, and (d) a testable prediction the class could check with a measurement.
Question 1
Sight, hearing, touch, smell, taste (1). One example, e.g. a hand that was in warm water feels lukewarm water as cold; two equal lines look different lengths; you cannot tell 37 °C from 39 °C by touch (1). [2 marks]
Match each rough guess to a better instrument
Bath water → C; Desk → A; Schoolbag → D; A minute → E; Juice → B. 1 mark each. [5 marks]
Fill the gap
observation; inference; wrong; prediction; testable. Not needed: guess, opinion. 1 mark each. [5 marks]
Observation or inference? Sort it
Observation: bread crumbs on the table; thermometer reads 27 °C; bin full to the top; magpie swooping near the gate; ground wet near the drinking tap. Inference: someone made a sandwich here; lunch was busy today; the magpie is guarding a nest. All 8 = 3; 6 or 7 = 2; 4 or 5 = 1. [3 marks]
Read the data: eyes versus a tape measure
2. Desk 20 cm; door 24 cm (1). The door height (1). [2 marks]
3. Guesses by eye were off by 2 to 24 cm, and bigger objects were off by more (1). A tape measure gives an exact number with a unit that other people can check and repeat (1). [2 marks]
Question 4
Marking guide: (a) 1 an observation, e.g. the leaves hang down, the soil feels dry; (b) 1 an inference, e.g. nobody watered it over the weekend; (c) 1 a different inference, e.g. the sunny window made the room too hot; (d) 1 an “If … then …” prediction and 1 for something measurable in it. [5 marks]
Model answer: (a) The leaves are drooping and the soil feels dry. (b) Nobody watered the plant over the weekend. (c) The sun through the window made the room too hot for it. (d) If we give the plant 250 mL of water now, then by tomorrow morning its tallest stem will stand at least 5 cm higher above the pot, measured with a ruler.
Common error: writing an inference as an observation, e.g. “I observed that the plant was thirsty”. Thirsty is worked out, not seen.