The missing digit could be any number from 0-4 because if it were any from 5-9 then it would be rounded to 16,000.
Answer:
robert is 12 years old
Step-by-step explanation:
robert's age=x
40=3x+4
that's the equation
40=3x+4
=36=3x
x=12
5.4
That's your answer because if the number is 5 or larger, you round up. Because 6 is larger than 5, it rounds up to zero and then the 3 becomes a 4.