Demonstrate the rules of 'just adding zeros' when multiplying by 10, 100, 1,000 etc. by starting with an object. Multiplying the object by the number and just adding the zeros lets kids see the process without confusing it without actual numbers. Then, have them multiply numbers with straight multiplication and by adding the numbers within a place value chart. They will see that only the first number changes to reflect how many 100s, 1,000s etc. they are multiplying.