5.2. The number 80 should be divided into two parts so that half of the larger part is 10 more than the smaller part.

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\text { (4-5 grades) }
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5.2. Let's denote half of the larger part by $x$. Then the smaller part is $x-10$, and the larger part is $2x$. We have the equation: $2x + x - 10 = 80$, from which $x = 30$, i.e., the smaller part is $30 - 10 = 20$, and the larger part is $2 \cdot 30 = 60$.