The expression [tex]2.4 \times 7[/tex] can be estimated by [tex]2 \times 7[/tex], so the answer would be roughly 14 here. I'm not sure where you got that '1' from.
Directly below that problem, we have the expression [tex]63.2 \times 0.78[/tex] which can be estimated by computing [tex]63 \times 1[/tex] which simplifies to 63. The '1' is from rounding to the nearest whole number.
Other than that, everything else looks correct on your worksheet.
