Shen’s mother gave him $10 to go buy groceries. He picked up a gallon of milk for $3. 49, three pounds of oranges that cost $1. 14 per pound, and a box of cereal for $3. 46. Shen used front-end estimation to determine whether he had enough money for the groceries. How much did he estimate the total cost would be? He estimated that he had about $7 worth of groceries. He estimated that he had about $9 worth of groceries. He estimated that he had about $10. 30 worth of groceries. He estimated that he had about $10. 40 worth of groceries.