"457-387等于几"...457-387等于几

　"457+386等于几"...457+386等于几

　"398+574等于几"...398+574等于几

　"457+326等于几"...457+326等于几

　"457+363等于几"...457+363等于几

　"398+497等于几"...398+497等于几

　"487-398等于几"...487-398等于几

　"457+284等于几"...457+284等于几

　"427+398等于几"...427+398等于几

　"457+384等于几"...457+384等于几