Primary 6 · Solids · Question type 10.3
Start with 6 faces for each cube, then subtract one for every glued face and one for a face resting on the table.
Try the question yourself, or watch the lesson first.
Primary 6, on the MOE Primary Mathematics syllabus.
The lesson · 2 minutes 20 seconds
Watch: 7 unit cubes glued into one solid, and which of them the brush reaches on exactly 4 faces
Another worked example
Ten unit cubes are glued together to form the staircase shown, one cube deep, with columns 4, 3, 2 and 1 cubes high. The outside is painted, but the faces resting on the table are not painted. How many faces of the cubes are painted altogether?
The working · Six lines
Written out in full, the way it should appear on paper.
The answer is 32.
Practise · Modelled on top school exam questions
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Try it yourself
Start with the outside faces and account for shared joins.
Seven unit cubes are glued together to form the solid shown. The whole outside of the solid is then painted, including the faces that rest on the table. How many faces of the cubes are painted altogether?
Ans: 30
The practice plan adds more questions and saved progress.
The last type constructs a flat figure on a grid. Adding and Removing Cubes from Views →