填一填．
70+70+70+70= × =
51×4= × + × = + =
700+700+700= × =
3×400= + + =
× =90+90+90+90= ．
填一填．
70+70+70+70= × =
51×4= × + × = + =
700+700+700= × =
3×400= + + =
× =90+90+90+90= ．
米是 29
米；比30米少 
的意义是 
表示 ．
×
=
． ．
的 
是多少？算式是 ．
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