Explanation:
903.6 ÷ 25.1 = 36 (exact answer).
900 ÷ 30 = 30 (estimated). As 903.6 near to 900 and not to 1000, and 25.1 near to 30 and not to 25 the equation is 900 ÷ 30 = 30.
760.38 ÷ 0.38 = 2001 (exact answer).
In the estimated answer Im not so sure about it so I leave you four choices.
1. 800 ÷ 0.40 = 2000 (rounded to the nearest ten)
2. 800 ÷ 0.00 = Infinity (0.38 close to a whole)
3. 800 ÷ 1 = 800 (0.38 not close to a whole)
4. 800 ÷ 40 = 20 (possibly the wrong answer not even close to 0.38)