Post on 28-Mar-2015
Let’s count the Faces on a cube
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Use the letter F for the number of Faces
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How many Faces?
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F =
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F = 6
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= ? E CF
Fill in the table©
6
= ? E CF
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How many Corners?
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C = ©
C = 8 ©
6
= ? E CF
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86
= ? E CF
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How many Edges?
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E =
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E = 12
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86
= ? E CF
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1286
= ? E CF
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Equation
F + C – E =
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Equation
6 + 8 – 12 =
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Equation
6 + 8 – 12 = 2
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21286
= ? E CF
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A Pyramid
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F = ©
F = 4 ©
4
21286
= ? E CF
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C = ©
C = 4 ©
44
21286
= ? E CF
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E = ©
E = 6 ©
644
21286
= ? E CF
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Equation
F + C – E =
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Equation
4 + 4 – 6 =
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Equation
4 + 4 – 6 = 2
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644
21286
= ? E CF
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2644
21286
= ? E CF
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For homework see whether you can do the same calculation
for
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an icosahedron
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and a football
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How many Corners?
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4 on top
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4 on the bottom©
1
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1 2
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1 2
3
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1 24
3
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1 24
3
5
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1 24
3
5
6 ©