Finding 10, 100 or 1000 less 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 subtract 10, 100 or 1000

I think of a number. I subtract 100, then subtract 1000. My answer is 3450. What was my number?

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?