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? a he estimated that he had about $7 worth of groceries. b. he estimated that he had about $9 worth of groceries. c. he estimated that he had about $10.30 worth of groceries. d. he estimated that he had about $10.40 worth of groceries.