INITIATION À L``ARITHMÉTIQUE ET À L``ALGÈBRE

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Exercices d*arithmétique 7e année
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Exemple!@!67 + 78 + 12 = 67 + (78 + 12) = 67 + 90 = 157!
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+%,?!2'62'/101&!2'1-1+%30%&!Wassociativité et commutativitéE8!V3!%==%0<!26,'!-.*-,*%'!2.'!%?%42*% !!FM
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le produit de plusieurs facteurs ne dépend ni de l4ordre dans lequel sont écrit les facteurs, ni de
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Exemples. WLes parties grisées ci-dessous sont effectuées oralement et non par écrit.E
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Prolongement.!!
A.!La notation puissance.
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+;1-'/'%!-%!2'6+,/0!%&0!+%!'.&&%47*%'!*%&!4Q4%&!=.-0%,'&<!2,/&!+;,0/*/&%'!la notation puissance!@!
6·12 = WF`GE`WF`F`GE!Y!WF`F`FE`WG`GE = 23 · 32!!!!W%3!='.3b./&!@!deux au cube fois trois au carréE!
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B.!Exercice oral.!a1-6426&%!%3!produits!+%!=.-0%,'&!premiers!06,&!*%&!3647'%&!composés!≤!#FN8!
Exemple. 120 = #F`!#N!Y!WG!`!IE!`!WF!`!JE!Y!F!`!F!`!F!`!G!`!J!Y!23 · 3 · 5!
Rappel. U3!3647'%!%&0!+/0!premier!&;/*!.+4%0!%?.-0%4%30!+%,?!+/5/&%,'&8!
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QUELQUES PROBLÈMES D.ARITHMÉTIQUE 7e
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