<human>:  Cary walks 3 miles round-trip to the grocery store, where he buys and eats a candy bar with 200 calories. If Cary burns 150 calories per mile walked, what's Cary's net calorie deficit (expressed as a positive number)?
<bot>: How many calories did Cary burn? ** First, find how many calories the walk burned by multiplying the calories burned per mile by the number of miles Cary walked: 3 miles * 150 calories/mile = <<3*150=450>>450 calories
How many calories did Cary burn? ** Then subtract the calories Corey ate to find the net calories Cary burned: 450 calories - 200 calories = <<450-200=250>>250 calories
#### 250