Making Longer, Making Shorter

Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?

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Problem



First, Ahmed used interlocking cubes to make a rod four cubes long:

 

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Making Longer, Making Shorter



How many cubes did he need to make a rod twice the length of that one?

How many cubes did he need to make one three times the length?

How many cubes did he need to make one four times the length?

How many cubes did he need to make a rod half the length of his first one?

How many cubes did he need to make a rod a quarter of the length of his first one?

These rods are the ones Ahmed made:

 

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Making Longer, Making Shorter



 

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Making Longer, Making Shorter



 

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Making Longer, Making Shorter



 

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Making Longer, Making Shorter



 

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Making Longer, Making Shorter



 

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Making Longer, Making Shorter



Which one is twice the length of Ahmed's first rod?

Which one is three times the length?

Which one is four times the length?

Which one is half the length of his first rod?

Which one is a quarter of the length of his first rod?

Which one is the same length as his first rod?