Finding 10, 100 or 1000 more than a given number

Maths

Mrs Crane has completed the following number line,  is she correct?

Complete this function machine by deciding if you need to add 10, 100 or 1000

I think of a number. I add 10, then add 100. My answer is 7820. What was my number?

Using the digit cards, 3, 5, 7 and 8, which of the following numbers is the greatest number I can make?

Using the digit cards, 3, 5, 7 and 8, which of the following numbers is the smallest number I can make?

If the target was to make a number closest to 2000, who has won?