Página — Matematica 3 (pág. 167)

Página 60Tablas de multiplicar

\begin{aligned}(4.\ 5\cdot9&=5\cdot(4+\overbrace{\quad5\quad}^{})\\&=5\cdot\overbrace{\quad4\quad}^{}+5\cdot\overbrace{\quad5\quad}^{})\\&=20+\overbrace{\quad25\quad}^{}\\&=\overbrace{\quad45\quad}^{}\end{aligned}

Página 61

\begin{aligned}a.\ 2\cdot7&=\overbrace{\quad2\quad}^{}\cdot(\overbrace{\quad5\quad}^{}+\overbrace{\quad2\quad}^{})\\&=\overbrace{\quad2\quad}^{}\cdot\overbrace{\quad5\quad}^{}+\overbrace{\quad2\quad}^{}\cdot\overbrace{\quad2\quad}^{})\\&=\overbrace{\quad10\quad}^{}+\overbrace{\quad4\quad}^{}\\&=\overbrace{\quad14\quad}^{}\end{aligned}

\begin{aligned}6.4\cdot9&=\overbrace{\quad4\quad}\cdot(\overbrace{\quad6\quad}+\overbrace{\quad3\quad})\\&=\overbrace{\quad4\quad}\cdot\overbrace{\quad6\quad}+\overbrace{\quad4\quad}\cdot\overbrace{\quad3\quad})\\&=\overbrace{\quad24\quad}+\overbrace{\quad12\quad}\\&=\overbrace{\quad36\quad}\\ \end{aligned}

a.

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Matemática·3°Básico

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