Addition of zero to numbers quiz online. This is an interactive online quiz. The trick kids will learn is the fact that if you add zero to a number it will always stay the same. For example, 12 + 0 = 12. There are similar math problems in this quiz. After solving each problem, type the answer in the space provided and submit for feedback. Repeat the exercise if your feel your skills in adding zero are not good enough. Parents and teachers can use this online test to check their kid’s level of understanding. This activity is for children in kindergarten, 1st, , 2nd and 3rd grades.