- Focus on the ones digit when rounding to the nearest \(10\). - Decide whether the number is closer to the lower ten or the next ten. - Check that your rounded number is a multiple of \(10\).

1. The ones digit is \(3\), which is less than \(5\). 2. The tens digit stays \(6\), and the ones digit becomes \(0\). 3. Therefore, \(263\) rounds to \(260\).

The tens digit stays \(6\), so \(263\) rounds to \(260\).

- Count the small tick spaces from the left end. - Compare the spaces from the marker to each labeled ten.

1. The ticks are one apart. The marker is at \(642\). 2. It is \(2\) from \(640\) and \(8\) from \(650\), so the nearer ten is \(640\).

\(642\); nearer to \(640\).

- The ten before \(365\) keeps the same tens digit. The next ten has one more ten. - Think about how a smaller halfway number, like \(15\), rounds.

1. The two neighboring tens are \(360\) and \(370\). 2. A halfway number rounds to the greater ten, so \(365\) rounds to \(370\).

\(360\) and \(370\); rounded to \(370\).

- Use the labeled endpoints and the tick spacing to determine each marker's value. - Compare each marker with the halfway tick between the neighboring tens. - For a marker exactly halfway, use the rounding convention.

1. Marker A is two 1-unit ticks past \(450\), so it represents \(452\). It is closer to \(450\) than to \(460\), so it rounds to \(450\). 2. Marker B is at \(708\). It is closer to \(710\) than to \(700\), so it rounds to \(710\). 3. Marker C is at \(195\), exactly halfway between \(190\) and \(200\). A halfway value rounds to the greater multiple of \(10\), so it rounds to \(200\).

a) A: \(452\), rounded to \(450\) b) B: \(708\), rounded to \(710\) c) C: \(195\), rounded to \(200\)

- Use the endpoint labels and 1-unit tick spacing to locate the marker. - Identify the two multiples of \(10\) on either side. - Compare the marker's distance from those two endpoints.

1. A is at \(524\), between \(520\) and \(530\), and is closer to \(520\). 2. B is at \(607\), between \(600\) and \(610\), and is closer to \(610\). 3. C is at \(889\), between \(880\) and \(890\), and is closer to \(890\).

a) A: below \(520\); above \(530\); nearer \(520\) b) B: below \(600\); above \(610\); nearer \(610\) c) C: below \(880\); above \(890\); nearer \(890\)

- Find the tens just below and above each count. - A ones digit less than five means the lower ten is nearer. - Add your rounded counts; the exact total is not needed here.

1. \(143\) rounds to \(140\); \(276\) rounds to \(280\). 2. Add the rounded counts: \(140+280=420\).

Monday: \(140\) tickets. Tuesday: \(280\) tickets. Estimated total: about \(420\) tickets.

- Use the endpoint labels and 1-unit tick spacing to read A. - Compare the number of tick intervals from A to each endpoint. - If the distances are equal, recall the convention for a halfway value.

1. The tick spacing is \(1\), and A is at the middle tick between \(470\) and \(480\), so A represents \(475\). 2. The neighboring multiples of \(10\) are \(470\) and \(480\). 3. A is \(5\) away from each endpoint, so it is exactly halfway. 4. Distance alone does not choose an endpoint, so a convention is needed. A halfway value rounds to the greater multiple of \(10\), so \(475\) rounds to \(480\).

a) \(475\) b) \(470\) and \(480\) c) Exactly halfway d) The distances are equal, so a convention is needed; A rounds to \(480\).

- Identify the two consecutive multiples of \(10\) around the number. - Ask which place tells you where the number lies between those two tens. - Check whether the proposed rounded number is actually the nearer ten.

1. To round to the nearest \(10\), use the ones digit, not the tens digit, to decide whether to round up or down. 2. The ones digit of \(342\) is \(2\), so the number is closer to \(340\) than to \(350\). 3. Therefore, \(342\) rounds to \(340\).

Noah looked at the wrong digit. For rounding to the nearest \(10\), the ones digit controls the decision. Since the ones digit is \(2\), \(342\) rounds to \(340\).

- Read the endpoint and midpoint labels from the number line. - Consider the whole-number ticks on each side of the midpoint. - Remember what happens to the tick exactly halfway between the two tens.

1. The endpoints are \(230\) and \(240\), with midpoint \(235\). 2. The whole-number ticks strictly between the endpoints are \(231\) through \(239\). 3. The values \(231\), \(232\), \(233\), and \(234\) lie to the left of the midpoint and are closer to \(230\). 4. The midpoint \(235\) rounds to \(240\), so it is not included.

\(231\), \(232\), \(233\), and \(234\)

- Think about the halfway points on both sides of \(480\). - Include a boundary value only if it rounds to \(480\). - Check the next whole number after your proposed greatest value.

1. \(475\) is halfway between \(470\) and \(480\), so it rounds to \(480\). 2. Values through \(484\) are closer to \(480\) than to \(490\). 3. \(485\) is halfway between \(480\) and \(490\) and rounds to \(490\). 4. Therefore, the least possible count is \(475\) and the greatest is \(484\).

a) \(475\) b) \(484\)