An average person in the united states throws away 4.5 × 10² g of trash per day. in 2013, there were about 3.2×106 people in the u. s.
about how many grams of trash was thrown away in the united states in 2013?

Since there are 4.5*10^2 grams of trash per day per person, we multiply that by 3.2*10^6 for everyone in the US and then multiply that by 365 to get how much in a year, which is 525600000000 or 5.256*10^11 (I think it's 11)

Where is your question?