Grade 8 · Math · Unit 16 of 18
Metric Giants & Composite Shapes
Mega to pico, and shapes stuck together
What your child practises
Converting between metric units from pico to tera using powers of ten, and finding the perimeter, area, volume and surface area of shapes made from several simpler shapes.
Ontario Curriculum expectation: E2.1, E2.3 · very large and very small metric units, and perimeter, area, volume and surface area of composite shapes
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
1 terametre (Tm) = 10 to what power, in metres?
1 Tm = 10 m
answer box
Show answer
12
Hint: Mega is 10⁶, giga is 10⁹ and tera is 10¹². Count the zeros in the number of metres.
Question 2
A cube with edges of 7 cm sits on top of a box that is 12 cm long, 8 cm wide and 3 cm tall. What is the surface area of the whole solid, in square centimetres?
answer boxcm²
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508 cm²
Hint: Start with the box: 312 cm². The cube's bottom covers part of the box's top, but the cube's own top face takes that area back. So just add the cube's 4 side faces: 4 × 7².
Question 3
Convert 95 m to km.
answer boxkm
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0.095 km
Hint: km is 10³ times as large as m, so divide by 1000. Move the decimal point 3 places to the left.
Question 4
Tap the metric units from smallest to largest.
- metre
- picometre
- terametre
- gigametre
Show answer
picometre → metre → gigametre → terametre
Hint: Pico, nano, micro and milli are small. Kilo, mega, giga and tera are large. A greater exponent means a larger unit.
Question 5
A circular path has an outer radius of 4 m and an inner radius of 2 m. What is the area of the path, in square metres? Use π ≈ 3.14.
answer boxm²
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37.68 m²
Hint: Area of the big circle minus area of the small circle: 3.14 × (4² − 2²).
Question 6
Convert 11 Mm to m.
answer boxm
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11000000 m
Hint: Mm is 10⁶ times as large as m, so multiply by 1000000.