Question

match the expression to the best estimate of its difference. 12.3 - 7.98, 12.14 - 6.9, 10.78 - 5.2, 11.75 - 7.6, 11.15 - 4.75, 12 - 8, 12 - 7, 11 - 5, drag and drop items here (three times)

Explanation:

Step1: Analyze \(12.3 - 7.98\)

Round \(12.3\) to \(12\) and \(7.98\) to \(8\), so it matches \(12 - 8\).

Step2: Analyze \(12.14 - 6.9\)

Round \(12.14\) to \(12\) and \(6.9\) to \(7\), so it matches \(12 - 7\).

Step3: Analyze \(10.78 - 5.2\)

Round \(10.78\) to \(11\) and \(5.2\) to \(5\), so it matches \(11 - 5\).

Step4: Analyze \(11.75 - 7.6\)

Round \(11.75\) to \(12\) and \(7.6\) to \(8\)? Wait, no, \(11.75\) is closer to \(12\)? Wait, \(11.75\) rounded to nearest whole is \(12\)? Wait, \(11.75\) is \(11 + 0.75\), so rounding to whole number is \(12\)? Wait, no, \(11.75\) is between \(11\) and \(12\), but \(0.75\) is more than \(0.5\), so rounds to \(12\). \(7.6\) rounds to \(8\)? Wait, no, \(7.6\) is closer to \(8\)? Wait, \(7.6\) is \(7 + 0.6\), so rounds to \(8\)? Wait, but \(12 - 8\) is one of the options. Wait, but let's re - check: \(11.75\approx12\), \(7.6\approx8\), so \(11.75 - 7.6\approx12 - 8\).

Step5: Analyze \(11.15 - 4.75\)

Round \(11.15\) to \(11\) and \(4.75\) to \(5\), so it matches \(11 - 5\). Wait, but let's correct: \(11.15\) is closer to \(11\) (since \(0.15\lt0.5\)), \(4.75\) is closer to \(5\) (since \(0.75\gt0.5\)). So \(11.15 - 4.75\approx11 - 5\).

Now, let's list the matches:

• \(12 - 8\): \(12.3 - 7.98\), \(11.75 - 7.6\)
• \(12 - 7\): \(12.14 - 6.9\)
• \(11 - 5\): \(10.78 - 5.2\), \(11.15 - 4.75\)

Answer:

• \(12 - 8\): \(12.3 - 7.98\), \(11.75 - 7.6\)
• \(12 - 7\): \(12.14 - 6.9\)
• \(11 - 5\): \(10.78 - 5.2\), \(11.15 - 4.75\)