A brief addition word problem has learners searching for the missing addend. They read about Mr. George, who already has five gallons of fuel in his car. Knowing the car can hold eleven gallons, they compute how many gallons he needs. This makes a good all-class warm-up, since the explanation and answer is written on the bottom half of the sheet. Simply cover it as learners try on their own and reveal the explanation as you review the process.