Which estimates use suitable nearby benchmarks? Select all that apply.

توضیح

The calculations 0.49 + 0.52 near 0.5 + 0.5 = 1, 29.7 - 10.2 near 30 - 10 = 20, and 12.1 × 3.9 near 12 × 4 = 48 all use close convenient values. The claim that 6.2 ÷ 0.2 is about 3 confuses division with a much smaller result; 6 ÷ 0.2 is 30.