In this exercise, each student received a hundreds chart and teamed up with a partner to explore sets of numbers, or "windows," arranged in squares on the chart. Their goal was to find a combination of four numbers that added up to a specific sum of 158. Using their knowledge of addition and estimation, the students demonstrated their problem-solving skills by showing their work step by step. After mastering the initial challenge, they had the opportunity to create their own sums, further enhancing their mathematical reasoning and collaboration skills. Well done, Grade 2 mathematicians!