Year 7 Maths • AC9M7N01 • Homework
Perfect Squares and Square Roots
Show enough working to make your reasoning clear. The questions cover all five curriculum elaborations.
Part A
Core understanding
Draw or describe a square array for 8², then calculate 8².
Write the inverse square-root fact for 15² = 225.
Use 32 = 30 + 2 and an area model to calculate 32².
Place √85 between consecutive whole numbers. Justify your bounds.
Write the first differences and second differences for 1, 4, 9, 16, 25.
Explain why a perfect square cannot end in 8.
A square tiled floor contains 196 tiles. Find its side length and perimeter in tile lengths.
A square has perimeter 60 cm. Find its area.
Part B
Reasoning and application
A student writes 27² = 20² + 7². Explain the error and calculate 27² correctly.
Without multiplying 24 × 24, use 23² = 529 and the pattern of odd differences to find 24².
A square lawn has area 400 m². A path 2 m wide is built inside along all four edges. Find the remaining lawn area.
A square storage area must cover at least 300 m² and have a whole-number side length. Find the shortest possible side and the resulting area.
Answer check
- 64
- √225 = 15
- 30² + 2×30×2 + 2² = 1024
- 9 < √85 < 10
- First: 3,5,7,9; second: 2,2,2
- Squares of final digits 0–9 never end in 8
- Side 14; perimeter 56
- Side 15; area 225 cm²
- Two 20-by-7 cross regions were omitted; 729
- Add 47; 576
- Inner side 16 m; area 256 m²
- 18 m; 324 m²