Finding the difference between two numbers either side of a whole thousand is the focus of these two maths worksheets. But, even those these look hard they do not need to be done using written methods. Remember all that counting on we have been doing in earlier years; it comes into its own now.
For example: finding the difference between 6002 and 5899.
Start with the 5899
Count on 1 to make 5900
Count on 100 to make 6000
Count on 2 to make 6002.
The difference is 1 + 100 + 2 = 103