Wykonajmy obliczenia.

Czerwony

$\underset{10+2}{\underbrace{12}}\cdot 3=\underset{10\cdot 3}{\underbrace{30}}+\underset{2\cdot 3}{\underbrace{6}}=36$

$\underset{10+3}{\underbrace{13}}\cdot 5=\underset{10\cdot 5}{\underbrace{50}}+\underset{3\cdot 5}{\underbrace{15}}=65$

$\underset{10+2}{\underbrace{12}}\cdot 4=\underset{10\cdot 4}{\underbrace{40}}+\underset{2\cdot 4}{\underbrace{8}}=48$

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Zielony

$\underset{90+9}{\underbrace{99}}:9=\underset{90:9}{\underbrace{10}}+\underset{9:9}{\underbrace{1}}=11$

$\underset{10+4}{\underbrace{14}}\cdot 7=\underset{10\cdot 7}{\underbrace{70}}+\underset{7\cdot 4}{\underbrace{28}}=98$

$\underset{20+19}{\underbrace{38}}:2=\underset{20:2}{\underbrace{10}}+\underset{18:2}{\underbrace{9}}=19$

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Żółty

$80:4=20$

$\underset{20+3}{\underbrace{23}}\cdot 3=\underset{20\cdot 3}{\underbrace{60}}+\underset{3\cdot 3}{\underbrace{9}}=69$

$\underset{10+5}{\underbrace{15}}\cdot 5=\underset{10\cdot 5}{\underbrace{50}}+\underset{5\cdot 5}{\underbrace{25}}=75$

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Niebieski

$\underset{10+4}{\underbrace{14}}\cdot 6=\underset{10\cdot 6}{\underbrace{60}}+\underset{4\cdot 6}{\underbrace{24}}=84$

$\underset{60+6}{\underbrace{66}}:2=\underset{60:2}{\underbrace{30}}+\underset{6:2}{\underbrace{3}}=33$

$\underset{70+42}{\underbrace{112}}:7=\underset{70:7}{\underbrace{10}}+\underset{42:7}{\underbrace{6}}=16$