Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
Imagine we have four bags containing numbers from a sequence. What numbers can we make now?
Choose four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?
Can you find out what is special about the dimensions of rectangles you can make with squares, sticks and units?
Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?
We received lots of insightful comments to this problem.
Go to last month's problems to see more solutions.
This article looks at how images, concrete apparatus and representations can help students develop deeper understandings of abstract mathematical ideas.
Collect as many diamonds as you can by drawing three straight lines.