On Monday, while at work on the farm, Jeremy picks 100 oranges. On Tuesday, together with his brother, they pick thrice as much. On Wednesday he feels tired and is only able to pick 70 oranges. What's the total number of oranges they have? Let's be accurate as possible.
On Monday he picks 100 oranges. On Tuesday, they pick thrice as much, which will be 3 * 100 = 300 oranges. The total number of oranges picked now is 300 + 100 = 400 oranges. On Wednesday, he adds 70 more, which will now be 400 + 70 = 470 oranges.
The answer: 470.