Find the missing value: 12 + ? = 28. What is the missing value?

To find the missing value in the equation 12 + ? = 28, you need to determine what number, when added to 12, equals 28.

Starting with the equation, you can isolate the missing value by subtracting 12 from both sides. This gives you:

? = 28 - 12

When you perform the subtraction, you find:

? = 16

This indicates that the missing value is 16. This matches with the second choice, making it the correct answer. Understanding the basic operation of addition and how to manipulate equations to find unknown values is crucial in solving this type of problem.