Adding Whole Numbers Chapter 4 Lesson 3

Easy:
1)Answer the following questions without a calculator:
a)154+146
b)987+123

Medium:
2)Three kids collect baseball cards. Raymond has 359 baseball cards, Andy has 223 baseball card and Taylor has 129 baseball cards.
a)How many baseball cards does everyone have all together?

Hard:
3) To raise money to help Haiti from the earthquake , Mr.Graham sold trapezoid cookies in a vending machine. The machines takes only dimes. There had been 10 machinesholding 500,320, 530,960,120,350,990,190,290 and 570 cookies.
5a)