I never asked about certificates of deposit before. Recently, I got a certificate of deposit with principal, tax and interest written on it, and I was stupid because I don't know anything about these terms!
When I got home, I began to ponder. But after thinking for a long time, I still have no clue, but I am full of doubts. I have no choice but to ask my grandmother and teacher shamelessly. I asked doubtfully, "Grandma, what does the headmaster do?" "The principal is the original amount deposited in the bank, which is called the principal." Grandma said. "Then why is the amount written on the certificate of deposit more than the actual principal after withdrawing money?" I asked again. "That's because the total amount on the deposit certificate after withdrawal is obtained by adding the original principal (interest minus 20% tax). You understand this time! " But I know a thing or two. Grandma finally listed the formula and told me: for example, the annual interest of1000 yuan is X yuan, then the annual interest of 10000 yuan is1000 yuan. The tax is 100 x times 0.2. 100x-(100x-(100x 0.2) can get pure interest. The net interest plus the money actually saved is the total amount due (RMB). I then asked, "Grandma, if I want to withdraw money in advance, how should I calculate the interest?" Grandma said: "In that case, the deposit interest will be calculated according to the current deposit interest, and it is best not to withdraw it in advance as a last resort."
This time, I learned a lot about saving, which broadened my horizons and increased my knowledge, but it also made me feel that mathematics is actually around us. We should learn math well and use it.
Math is good, use it to solve some common problems in life.
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