If we have to subtract 18 cars from 20 cars. Then in one’s column, 0 – 8 does not make any sense, so we must regroup one of the two tens such the 0 now becomes 10. Now 10 – 8 = 2. You can count it using your hands. Count fingers of your both hands, 1,2,3,4,5,...
英语翻译People often say,“Children can’t do math problem,it’s because parents can’t do their children’s homework.” Here’s an example to show what I mean.The other day my daughter brought home her math homework.“I have to subtract (减) 179 from 20
The picture on the right shows a modern electronic calculator.It can add subtract multiply and divide.It can also calculate percentages and 14 roots. This picture shows a computer.Computers are very 15 calculating machines.In a flash a computer can do a calculation that you could not do in ...
Everyone knows at least two — his orher own language and the international language of numbers.Ancient numbersIn ancient times,people wrote numbers in many different ways.However,they nearly all countedin tens.ZeroThe system ofnumbers today consists of the numbers from 1 to 9 and 0.The ...