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Month Mania

Can you design a new shape for the twenty-eight squares and arrange the numbers in a logical way? What patterns do you notice?

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Noah saw 12 legs walk by into the Ark. How many creatures did he see?

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Writing Digits

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?


Stage: 1 Challenge Level: Challenge Level:2 Challenge Level:2

Chiu from Arcadia High School and Harry from St James' School sent in well explained solutions. Harry describes how he solved the problem:

The answer is 6 students. I numbered each of the students, 1 for the front and 25 for the back. Julia was obviously no. 19. I counted from 25 back 14 places (starting with 25 so the solution would be right). I found that Urvisha was no. 12. Then I counted the numbers between 12 and 19 and got 6.

Chiu drew a diagram to help answer the problem:

From the picture above, there are 25 students queuing in a straight line. Since Julia is the 19th from the front, Urvisha is the 14th from the back, which means there are 6 students between Julia and Urvisha.