4th Grade Rounding Whole Numbers Test Solutions and Scoring (PDF)

1. The ones digit 2 is less than 5, so keep the 7: \(470\).
2. The tens digit 4 is less than 5, so keep the 8 hundreds: \(6,800\).
3. The hundreds digit 0 is less than 5, so keep the 3 thousands: \(53,000\).
4. The ten thousands digit 8 is 5 or more, so round 2 up to 3: \(300,000\).

Scoring: half a point for each correct answer.

1. The point is between 8,740 and 8,750. It is closer to 8,750: \(8,750\).
2. Between 8,700 and 8,800, the halfway point is 8,750. The point is left of 8,750, so it rounds down: \(8,700\).

Scoring: 1 point for each correct answer.

Halfway between 2,000 and 3,000 is 2,500, which rounds up to 3,000. 2,499 rounds down to 2,000.

Halfway between 3,000 and 4,000 is 3,500, which rounds up to 4,000. 3,499 rounds down to 3,000.

Smallest: \(2,500\). Greatest: \(3,499\).

Scoring: 1 point for each correct number.

1. \(6,348\) rounds to \(6,000\); \(2,719\) rounds to \(3,000\). \(6{,}000 + 3{,}000 = 9{,}000\). about \(9,000\)
2. \(73,462\) rounds to \(70,000\); \(28,905\) rounds to \(30,000\). \(70{,}000 – 30{,}000 = 40{,}000\). about \(40,000\)

Scoring: 1 point for each estimate. Give half a point if the numbers are rounded correctly but the final arithmetic is wrong.

Ten thousand: 1 is followed by 6, so round up to \(420,000\).

Thousand: 6 is followed by 5, so round up to \(417,000\).

Hundred: 5 is followed by 7, so round up to \(416,600\).

\(420,000\); \(417,000\); \(416,600\)

Scoring: 1 point for two correct answers, 2 points for all three.

A number rounds to \(12,000\) from \(11,500\) up to \(12,499\).

\(11,499\) is below 11,500, so it rounds to 11,000. It could not be the exact attendance.

\(12,500\) is halfway and rounds up to 13,000. It could not be the exact attendance.

Scoring: 1 point for each correct answer with a reason.

1. \(14,628\) rounds to \(15,000\). \(9,375\) rounds to \(9,000\).
2. \(15{,}000 + 9{,}000 = 24{,}000\). about \(24,000\)
3. \(15{,}000 – 9{,}000 = 6{,}000\). about \(6,000\)

Scoring: 1 point for each part.

1. The hundreds digit is 3 and the digit to its right is 9, so round up: \(7,400\).
2. Sofia kept the hundreds digit. The digit to its right (9) is 5 or more, so the hundreds digit must go up by 1.
3. The thousands digit is 7 and the digit to its right is 3, so keep it: \(7,000\).

Scoring: 1 point for each part.

\(3,874\) rounds to \(4,000\). \(4,129\) rounds to \(4,000\). The estimate is \(8,000\).

\(7,003\) is far from \(8,000\), so it is not reasonable. He forgot to regroup.

Correct sum: \(3{,}874 + 4{,}129 = 8{,}003\). \(8,003\)

Scoring: 1 point for the estimate and decision. 1 point for 8,003.