Answer:
2/3 * 660
Explanation:
If we convert 65% to a decimal, we get 0.65.
First, it will helpful to find exactly what is 65% of 668:
0.65 * 668 = 434.2 and thus 65% of 668 is exactly 434.2.
Similarly, if you convert 2/3 to a decimal, you get 0.66 repeating.
2/3 * 660 = 440 which is only 10.2 units larger than 434.2. Thus, 2/3 * 660 is the most accurate estimate of 65% of 668.