Material needs for battery-powered or solar-powered calculators in supermarkets.
1. How to understand, comprehend, participate in modifying or self-making the calculation logic content of the calculator;
2. The content about the power consumption of the calculation, and the lifespan of solar energy, rechargeable batteries and the like.
1. How to understand, comprehend, participate in modifying or self-making the calculation logic content of the calculator;
2. The content about the power consumption of the calculation, and the lifespan of solar energy, rechargeable batteries and the like.
1<词>，2，3/段\，4{节}，5(章)。