When we find the missing number in addition , we have to subtract the given number from answer.
When we find the missing number in subtractin ,
if we have to find the second number , we have to subtract the answer from the given number. 345 - ............ = 220
345 - 220 = 125
if we have to find the first number , we have to add the given number and the answer.
............ - 150 = 600
150 + 600 = 700
