One day, my family took me to the supermarket to buy things. I jumped up and down all the way and was very excited.
After going in, we went shopping for a while, and we brought four bags of laundry detergent. Walking to the stationery section, grandma asked me if I wanted stationery. I went to the bookshelf and looked at it. ...
I bought the following products at the cashier: four bags of laundry detergent, one bag 18.5 yuan; Ten packs of toilet paper and one pack of 4.5 yuan; A mechanical pencil, a 2.5 yuan; Three pens and one from 5.5 yuan.
After checking out, my grandfather suddenly asked me, "haven't you learned decimals recently?" Can you work out the total price of every commodity you bought today with a pen, and then work out how much it costs? "
"Yes, why not? Can't be wrong! " I answered him confidently.
Do it. I took a piece of advertising paper from the supermarket, took out my pen and immediately counted it in the blank.
My idea is this: four bags of laundry detergent, each bag 18.5 yuan, just use multiplication directly; A * * * ten packs of toilet paper, each pack of 4.5 yuan, can be calculated by moving the decimal point of this decimal point to the right; There is only one in mechanical pencil, just add it at the end; There are three more, which are also multiplication calculations.
So I figured it out. First, I use 4× 18.5=74 yuan (the teacher said that an integer multiplied by a decimal equals a decimal, but if this number multiplied by two numbers is zero, the result is an integer) to calculate the total price of laundry detergent; Then, use 10×4.5=45 yuan (a decimal is multiplied by 10, and moving the decimal point to the right is the result of this formula) to calculate the total price of toilet paper; Then use 3×5.5= 16.5 yuan to calculate the total price of the pen. The total price of everything I bought today has been worked out. It's time to calculate the cost. Comprehensive formula 74+45+ 16.5+2.5=
138 (yuan) (when talking about decimal addition, the teacher emphasized that the same numbers should be aligned when the columns are vertical), and the money spent was calculated.