Final answer:
The smallest possible value of Liam's number, when having two decimal places and rounded to one significant figure as 0.7, is 0.65. The largest possible value is 0.74.
Step-by-step explanation:
Liam thinks of a number with two decimal places and when rounded to one significant figure, the number becomes 0.7.
To determine the smallest possible value of Liam's number, we need to consider the lowest number that would round up to 0.7 at one significant figure. That would be 0.65, because if it were any lower, the number would round down to 0.6.
Similarly, to find the largest possible value of Liam's number, we look for the highest number that would still round down to 0.7, which is 0.74. If it were any higher, it would round up to 0.8.