What is the sum of the missing numbers? Solution: 16 = 4 squared, 49 = 7 squared
Therefore, the missing squared numbers between 16 and 49 must be 5 and 6.
Hence, the sum of the missing numbers = 25 + 36 = 61.
Advice: if possible, when dealing with big numbers, break them up into small numbers, like the digits on your hand, because many of us do not know what 14 squared is without a calculator, and you may not be allowed to use a calculator.
In my time in high school, there were no calculators, just that d**n slide rule.