Final answer:
The highest number among a) 8.5, b) 4, c) 2, and d) 6.5 is 8.5.
Step-by-step explanation:
The highest number among a) 8.5, b) 4, c) 2, and d) 6.5 is 8.5.
To determine the highest number, we compare each number with the others.
When comparing 8.5 with 4, we can see that 8.5 is greater.
When comparing 8.5 with 2, 8.5 is still greater.
Lastly, when comparing 8.5 with 6.5, 8.5 is again greater.
Therefore, 8.5 is the highest number among the given options.