加减练习一年级数学课件
日期:2010-11-05 11:38
14+3–9=19–9+9=18–10–4=8+7–9=18–8+5=17–10+6=8+6–9=15–5+9=8+5-9=14–4–5=1761019841561015713145101913410513-9+8=17–9+7=18–9–9=8+5–9=16–9+5=14–9+6=5+6–9=15–9+7=8+6-9=12–9+8=412815941347125111126131673119,
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