Teacher Jerry sends red envelopes to children on WeChat for New Year money. Let's understand the problem step by step. Jiajia is the first to receive and takes half of the money in the red envelope. Then Honghong takes 5 yuan. Finally, Dongdong takes all the remaining 6 yuan. We need to find out how much money Teacher Jerry originally put in the red envelope.
To solve this problem effectively, we'll use the working backwards method. This strategy is perfect for problems where we know the final result and need to find the original amount. Instead of trying to work forward from an unknown starting point, we begin with what we know for certain - that 6 yuan remained at the end. Then we reverse each operation step by step. We add back what was taken and double amounts when half was originally removed. This systematic approach will lead us directly to the original amount in the red envelope.
Now let's apply the working backwards method step by step. We start with what we know for certain: Dongdong took the remaining 6 yuan. This means before Dongdong took his share, there were exactly 6 yuan left. Next, we work backwards to before Honghong took her 5 yuan. If 6 yuan remained after she took 5 yuan, then before she took it, there must have been 6 plus 5, which equals 11 yuan. Finally, we work backwards to before Jiajia took half. If 11 yuan remained after Jiajia took half, then 11 yuan represents the other half. Therefore, the original amount must have been 11 times 2, which equals 22 yuan. So Teacher Jerry originally put 22 yuan in the red envelope.
Now let's verify our answer by working forward from 22 yuan to make sure it matches all the conditions in the problem. We start with the original amount of 22 yuan. First, Jiajia takes half of the money. Half of 22 is 11, so Jiajia takes 11 yuan, leaving 22 minus 11, which equals 11 yuan. Next, Honghong takes 5 yuan from the remaining 11 yuan. This leaves us with 11 minus 5, which equals 6 yuan. Finally, Dongdong takes all the remaining money, which is exactly 6 yuan, leaving zero yuan. This matches perfectly with the problem conditions, confirming that our answer of 22 yuan is correct.
今天我们来解决一个有趣的红包分钱问题。杰瑞老师给小朋友们发微信红包，佳佳第一个抢到红包，领走了一半的钱。接着红红领了5元钱，最后东东把剩下的6元钱全部领走了。那么杰瑞老师原本一共发了多少钱呢？让我们一步步来分析这个问题。
对于这种逐步分配的问题，我们可以使用倒推法来解决。倒推法的核心思想是从已知的最终结果开始，逐步向前推算每一步的情况，最终得到原始数值。这种方法特别适合处理连续操作的问题。
现在我们开始具体的倒推过程。首先，东东领走6元后红包就空了，这说明红红领钱之前红包里还有6元。接下来，红红领走了5元，所以红红领钱之前红包里应该有6加5等于11元。最后，佳佳领走了一半的钱，剩下的11元是另外一半，因此原来的总金额应该是11乘以2等于22元。
为了确保我们的答案正确，让我们进行验证。假设原始金额是22元，佳佳领走一半，也就是11元，剩下11元。接着红红领走5元，还剩6元。最后东东把剩下的6元全部领走，红包正好用完。这与题目描述完全吻合，证明我们的答案22元是正确的。
除了倒推法，我们还可以用代数方法来解决这个问题。设原始金额为x元，根据题意建立方程：x减去二分之x再减去5等于6，化简后得到二分之x等于11，所以x等于22元。倒推法直观易懂，特别适合这种分步骤的问题，而代数法更加系统化，适用于复杂的数学问题。无论使用哪种方法，最终答案都是22元。