20x20=400三位数加减法计算题练习44+932=199+398=801+60=814+551=75+505=481+21=665+1000=729+808=306+812=28+911=263+206=644+64=537+385=310+534=861+146=558+321=502+957=857+423=459+86=473+577=733+530=139+312=323+291=387+833=964+103=686+936=921+231=302+355=195+676=968+825=519+171=216+612=160+248=515+449=118+377=865+868=797-338=716-316=983-327=825-332=548-430=783-460=898-584=830-54=979-605=897-727=750-253=659-567=77-45=641-353=20x20=400940-456=979-488=680-502=637-631=911-75=599-481=834-776=569-366=975-883=995-775=985-807=136+471=345+427=622+190=437+270=683+181=903-786=81+519=525-412=736-675=461+433=833-732=961-600=718-608=188-14=166+262=419+489=811-796=230-177=275+421=395-46=487-35=391+589=252+6=696+266=999-921=220-3=397+455=256+728=726-501=168+750=694-149=651-615=332+384=361+331=515+483=156-25=878-128=423+49