Final answer:
To find the number that when added to 8 is less than 12, we set up and solve an inequality.
Step-by-step explanation:
To determine the sum of a number and 8 that is less than 12, we set up the inequality: x + 8 < 12. To solve for x, we isolate it on one side of the inequality by subtracting 8 from both sides: x + 8 - 8 < 12 - 8. This simplifies to x < 4. Therefore, any number less than 4 would satisfy the given inequality.