Final answer:
The smallest possible number that rounds to 350 to the nearest 10 and to 300 to 1 significant figure is 345.
Step-by-step explanation:
The student's question involves finding the smallest possible whole number given two different rounding conditions. Hannah's number, when rounded to the nearest 10, is 350, and when rounded to 1 significant figure, it is 300. To determine the smallest possible number, we need to consider the range of values for both conditions.
For the first condition, any number from 345 to 354 (inclusive) will round to 350 when rounding to the nearest 10. For the second condition, any number from 250 to 349 (inclusive) rounds to 300 when rounding to 1 significant figure.
Combining both conditions, the smallest number that meets both criteria is 345. This number rounds to 350 to the nearest ten and also rounds down to 300 to one significant figure.