For the common core standard 4.NBT.2, I created some practice sheets. Students write the word and expanded form of numbers. Students start by writing a three digit number. Then I added 3 more digits to the original number. Then I added 1-3 more digits to create a number in the millions. I am using these sheets for an intervention. The work would also be great for homework practice. Look at the preview. Please let me know what you think.