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Can you find a path from a number at the top of this network to the bottom which goes through each of the numbers $1$ to $9$ once and once only?
Can you design a new shape for the twenty-eight squares and arrange the numbers in a logical way? What patterns do you notice?
Lee was writing all the counting numbers from 1 to 20. She stopped for a rest after writing seventeen digits. What was the last number she wrote?