Starter quiz
- Which of these would you use centimetres to measure the height or length of?
- Length of a whale
- Height of a tree
- Length of your foot ✓
- Height of a house
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- What measurement is equal to 100 cm?
- '1 m' ✓
- I have a piece of ribbon that is 90 cm long. Is this ribbon shorter or longer than one metre?
- 'shorter' ✓
- How many 10 cm lengths will we get if we cut a 70 cm piece of ribbon up into 10 cm lengths?
- '7' ✓
- A whole length of string has been cut into 4 equal pieces and each of those pieces is 10 cm. What length is the whole piece of string?
- '40 cm' ✓
- Starting with the shortest, sort the five pieces of ribbon in order of length.
- 1⇔10 cm
- 2⇔40 cm
- 3⇔50 cm
- 4⇔70 cm
- 5⇔90 cm
Exit quiz
- The result of subtracting one number from another is known as ______
- a metre.
- the difference. ✓
- a centimetre.
-
- Which unit would you use to measure the height of a giraffe?
- mm
- cm
- m ✓
- kg
-
- Match the calculation to the difference.
- 12 cm - 5 cm =⇔7 cm ✓
- 20 cm - 8 cm =⇔12 cm ✓
- 14 cm - 8 cm =⇔6 cm ✓
- 15 cm - 6 cm =⇔9 cm ✓
- 17 cm - 6 cm =⇔11 cm ✓
What is the length of this feather?- '6 cm' ✓
What is the length of the pencil?- 3 cm
- 6 cm ✓
- 9 cm
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Jacob has broken his ruler and he can't see the zero. How can he measure the length of the leaf?- He can't.
- Place the leaf at the end of the ruler and read the measurement as usual.
- He can use it but he needs to find the difference. ✓
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Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- When measuring, it is more efficient to start at zero.
- The length of the object is the difference between the numbers on the ruler at the start and the end of the object.
- Measures can be given in metres or centimetres.
- Estimating helps us to decide if it is better to measure in centimetres or metres.
Common misconception
The length or height of an object is the numerical value at the end of the ruler (if not at zero).
If an object is not measured from zero, its length is the difference between the numerical value at the start and end of the object.
Keywords
Metre (m) - A metre is a standardised unit of measurement. We can abbreviate metre to m.
Centimetre (cm) - A centimetre is a standardised unit of measurement. We can abbreviate centimetre to cm.
Difference - The difference is the result of subtracting one number from another.
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