A student performs the following estimations: 24 + 190 = 210, 151 + 319 = 470, 974 + 1022 = 1990. Based on these estimations, what is the student's estimate of 452 + 5017?

This choice is incorrect because the student is not rounding down to the nearest ten or hundred. In the student's estimations, numbers are either rounded up or down to the closest ten or hundred. For example, in the estimation 151 + 319 = 470, 151 is rounded up to 200 and 319 is rounded down to 300. Therefore, for 452 + 5017, 452 would be rounded up to 500 and 5017 would be rounded down to 5000, summing up to 5500, not 5430.

This choice is incorrect because the student is not rounding both numbers up to the nearest hundred. The student's method seems to round to the closest ten or hundred rather than always rounding up. For instance, in the estimation 974 + 1022 = 1990, 974 is rounded up to 1000 and 1022 is rounded down to 1000. Following this pattern, 452 would be rounded up to 500, and 5017 would be rounded down to 5000, which sums up to 5500.

This choice is incorrect because it implies the student rounded down both numbers, which contradicts the student's method. For instance, in the estimation 151 + 319 = 470, 151 is rounded up to 200 and 319 is rounded down to 300. Therefore, for 452 + 5017, 452 would be rounded up to 500 and 5017 would be rounded down to 5000, resulting in a sum of 5500, not 5400.