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If four loaves of bread costs $8,
a loaf of bread and a bag of oranges costs $7,
and a loaf of bread, two bags of oranges and a basket of apples costs $17,
what is the cost of a basket of apples?
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Good problem for 2nd or 3rd grade students, who only can add, multiply and divide
integer numbers, but know nothing else in Math, including knowing nothing about equations.
Solving step by step
(1) If four loaves of bread cost $8, hence, one loave costs $8/4 = $2.
(2) If a loaf of bread and a bag of oranges costs $7, hence, a bag of oranges costs $7 - $2 = $5.
(3) If a loaf of bread, two bags of oranges and a basket of apples costs $17,
hence, a basket of apples costs $17 - $2 - 2 * $5 = $5. ANSWER
Solved mentally.
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To teach students solving such problems using equations means to suppress their common sense and initiative.
To teach them to solve it mentally, as I did in my post, means to develop their common sense and initiative.