Blue Plastic Base Ten Starter Kit

Q: Do these blocks interlock between the groups? Can the flats lock with the rods and units or can rods only lock with rods and flats with flats? Also, does the package include base ten stampers because the activity page asks the student to use base ten stampers to represent the number that is written in standard form. Just wondering if the stampers are included since the student is being asked to use them. Thanks!