Sue subtracted 2.9 from 20.9 and got 1.8. Explain why this is not reasonable

Because it is way to low even looking at it u can tell that it will still be in double diets

- - 20.9 is roughly 30.

- - 2.9 is roughly 3.

- - If Sue started with 30 and subtracted 3 from it, she would have 27.

- - 1.8 is nowhere near 27. It's not a reasonable answer.

(Actually, 20.9 - 2.9 = 18. So you can see where maybe she got her

digits from, but she made some kind of bad mistake in handling them.)