9+?−3=25 9+?-3=25 9+?−3=25
To find out which number is missing, we solve the entire exercise to know which number we will have to add to get a result of 25:
9−3=6 9-3=6 9−3=6
To make 6 equal to 25 we will have to add 19.
Let's verify:
25−6=19 25-6=19 25−6=19
19 19 19