估一估，算一算。:g/M.l3i
210÷28≈+l,X2k2D;B*?2F/H:` 653÷71≈(E9w:p:z5b4J 324÷43≈+h.F0U;R+`:T,e,P:N:g/M.l3i
257÷52≈-h3m.u'`0g:g:?3]/N7e1x;S1^ 548÷92≈4j1\7h3H0h6D+r:` 370÷88≈1[+m6T*];P0t:W;G3N:g/M.l3i