To determine which student correctly models the problem 1.25 + 0.4 using the hundredths grid, we need to analyze the shading in both Sophia's and Aiden's works.
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Understanding the Problem
- 1.25 can be represented as 1 whole (10x10 grid) and an additional 25 hundredths, which means we fill 25 squares on the second grid.
- 0.4 can be represented as 40 hundredths, which means we need to fill an additional 40 squares.
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Add the Values Together
- When combining 1.25 and 0.4:
- 1.25 = 100 + 25 = 125 hundredths
- 0.4 = 40 hundredths
- Total = 125 + 40 = 165 hundredths
- When combining 1.25 and 0.4:
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Comparing Sophia's Work
- Sophia shaded 1 whole grid (100 squares) and 2 columns plus 5 squares, which gives us:
- 100 + (2 columns * 10 squares/column) + 5 squares = 100 + 20 + 5 = 125 squares.
- On the second grid, she shaded 5 squares in the third column, 3 more columns (each with 10 squares), and 5 more squares, making:
- Shaded squares from the second grid = (5 columns * 10) + 5 = 30 + 5 = 35 squares.
- Total shaded by Sophia = 125 + 35 = 160 squares (or hundredths).
- Sophia shaded 1 whole grid (100 squares) and 2 columns plus 5 squares, which gives us:
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Comparing Aiden's Work
- Aiden shaded 1 whole grid (100 squares) and similar to Sophia, an additional 25 squares:
- 100 + (2 columns * 10 squares/column) + 5 squares = 125 squares.
- On the second grid, he shaded 4 squares in the third column, totaling:
- Total from second grid = 4 squares.
- Thus, Total shaded by Aiden = 125 + 4 = 129 squares (or hundredths).
- Aiden shaded 1 whole grid (100 squares) and similar to Sophia, an additional 25 squares:
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Conclusion
- Neither modeled the problem correctly, but Sophia was closer with 160 squares because it accounted for 1.25 + 0.4 = 165.
- Based on shading, Sophia effectively modeled the problem better than Aiden, but both are inaccurate since total should be 165.
So, my answer for Part A is Sophia as she shaded more of the correct total than Aiden.
If you have Part B or any more questions, please provide more context!