In the second grade, it is necessary to add, subtract, multiply and divide! ! ! thank you
Very simple: addition: 99+1= _ _ 67+3 = _ _ 8×1= _ _ 95-5 = _ _ 28+2 = _ _
Difficult: Subtraction: 99-89 = 87-67 = 9-6 = 89-9 =100-99 = 79-58 = 98-87 = Sorry, that's all.