1, the exchange rate is the ratio of the value of two currencies, so that means how much it costs to buy a currency, which is the price. Buying exchange rate and selling exchange rate are because banks make money by spreads, so according to your example, the exchange rate of US dollars against Japanese yen is 130.00/70, and the bank sells Japanese yen to you for US dollars at the price of 1, and he gives you 130 yen. Conversely, the bank buys you yen, and he gives you a dollar and asks you for 130.7 yen.

2. For banks, 130.00 is the selling price of Japanese yen, and 130.70 is the buying price of Japanese yen.

3. Cross division and cross multiplication are used to calculate the cross exchange rate. Because the foreign exchange price is basically based on the US dollar, people need to use formulas when calculating, for example, the name currency against the Japanese yen.

4. Multiplication and division occur because some currencies use direct quotation, that is, US dollars as numerator, and some currencies use indirect pricing, that is, US dollars as denominator, so there will be two cases of multiplication and division when calculating intersection. Specifically, it is very complicated, and I believe you don't want to understand it. . Then I suggest you look directly at the cross exchange rate, such as the pound against the euro, which can be found in major banks and portals.