What is 66,618,000 in expanded notation

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Tatiana wants to give friendship bracelets to her 32 classmates. she already has 5 bracelets, and she can buy more bracelets in packages of 4. write an inequality to determine the number of packages, p, tatiana could buy to have enough bracelets.

Plzzz answer both questions and i will give you 100 points