U7、Small volunteers —— mixed operations 七、小小志愿者——混合运算.
Lesson One 第一课 Let's buy some gifts for the children in the welfare home. 我们买些礼物送给福利院的小朋友吧。 We buy 10 pencil-boxes. 我们买10个文具盒。 Buy 40 notebooks and 30 pens. 买40本笔记本和30支钢笔。 What questions can you ask? 你能提出什么问题? Cooperative exploration 合作探索 How much does it cost to buy 10 pencil-boxes? 买10个文具盒要花多少钱? The price of each pencil case x the number of purchases = the total amount of money 每个文具盒的价格x买的个数=总钱数 twenty-nine by ten is two hundred and ninety 29x10 =290(元) The price of each pencil case is called unit price, the number of purchases is called quantity, and the total money is called total price. Can you give an example of their relationship? “每个文具盒的价格”叫作单价，“买的个数”叫作数量，“总钱数”叫作总价。你能举例说说它们的关系吗? If you buy 4 kilograms per kilogram of apples, you need 20 yuan. 如果每千克苹果5元，买4千克，就需要20元。 Five yuan per kilogram X four kg =twenty yuan 5元/千克X4千克=20元 Unit price x quantity = total price 单价x 数量=总价 If you buy four kilograms of apples for twenty yuan, then five yuan per kilogram of apples. 如果用20元钱买4千克苹果，那么每千克苹果5元。 Twenty yuan be divided by four kg equal to five yuan per kilogram 20元÷4千克= 5元/千克 Total price be divided by quantity equal to unit price 总价÷数量=单价 Use twenty yuan to buy apples, if five yuan per kilogram, can buy four kg. 用20元钱买苹果，如果每千克5元，可以买4千克。 Twenty yuan be divided by Five yuan per kilogram equal to four kilogram 20元÷5元/千克= 4千克 Total price be divided by unit price equal to quantity 总价÷单价=数量 How many pens can you buy for 40 yuan? 有40元钱，能买几支钢笔? How much does it cost to buy a notebook and pen? 买笔记本和钢笔一共要花多少钱? Use the money to buy a notebook plus the money to buy a pen... 用买笔记本的钱数加买钢笔的钱数..... Five times forty equals two hundred(yuan) 5x 40=200 (元) Eight times thirty equals two hundred forty (yuan) 8x30=240(元) Two hundred and two hundred and forty equals four hundred and forty (yuan) 200+240=440 (元) I list the comprehensive formula: what should be counted first? 我列综合算式:应先算什么? Five forty plus eight times thirty 5X 40+8X 30 = = (元) Will you calculate the following questions? 你会计算下面各题吗? Eleven times seven minus fifteen times four 11 X 7-15x4 one hundred and fifty plus great hundred plus six plus five 150+120+6X 5
Lesson two 第二课
Milk fifty-eight yuan/carton 牛奶58元/箱 Biscuit four yuan/ bag 饼干4元/包 Bread eight yuan per bag 面包8元/包 Egg yolks twelve yuan 蛋黄派12元/包 two hundred yuan to buy a case of milk twenty packets of biscuits, how much money left? 200元钱买1箱牛奶和20包饼干，还剩多少钱? The unit price of chocolate is twice the unit price of bread and egg yolk pie. 巧克力的单价是面包与蛋黄派单价和的2倍。 How many packets of chocolate can you buy for eighty yuan? 80元钱可以买几包巧克力? What more questions can you ask? 你还能提出什么问题? Cooperative exploration 合作探索 two hundred yuan to buy a case of milk and twenty packets of biscuits, how much money left? 200元钱买1箱牛奶和20包饼干，还剩多少钱? Ask how much money you need to use the total amount of money minus the amount of money spent, the total amount of money has been known, to find out the amount of money spent first... 求剩下多少钱需用总钱数减去花掉的钱数，总钱数已经知道了，要先求出花掉的钱数.... How much does it cost to buy a carton of milk and 20 packets of biscuits first. 先求买1箱牛奶和20包饼干一共要花多少钱。 Fifty-eight plus four by twenty 58+4x 20 Equals Fifty-eight plus eighty =58+80 equals one hundred and thirty eight =138 (元) Ask for more money. 再求还剩多少钱。 two hundred minus one hundred and thirty eight equals sixty-two 200-138=62 (元) Can also be listed comprehensive calculation, first calculate in small parentheses, small parentheses have two levels of operation. 还可以列综合算式计算，先算小括号里的，小括号里有两级运算..... two hundred minus fifty-eight plus four plus twenty 200-( 58+4X 20 ) equals two hundred minus fifty-eight plus eighty =200-( 58+80 ) Equals two hundred minus one hundred and thirty eight =200-138 equals sixty-two =62(元) Will you calculate the following questions? 你会计算下面各题吗? Twenty-five by( forty-four and two hundred and eighty-eight divided by sixteen) 25x( 44 + 288÷16) Two hundred and seventy divided by( fifteen and thirty divided by ninety) 270÷( 15x 30÷90 ) How many packets of chocolate can you buy for eighty yuan? 80元钱可以买几包巧克力? Find out the price of chocolate first, then... 先求出巧克力的单价，再…… I'm making a comprehensive formula like this, right? 我这样列综合算式，对不对? Eighty divided by eight and twelve times two 80÷(8+12) ×2 If you want to calculate the unit price of chocolate, you need to add parentheses. 如果列综合算式，要想先算出巧克力的单价，需要加中括号。 Eighty divided by [( eight and twelve) times two] 80÷ [(8+12)×2] Equal eighty divided by[ twenty times two] 80÷[20× 2] Equal eighty divided by forty =80 ÷40 Equal to two =2(包 ) Will you calculate the following questions? 你会计算下面各题吗? fifty-two by two hundred and eighty eight divided by one hundred and thirty minus one hundred and six 52x [288÷(130-106)] Three hundred fifty divided by seven times forty five 350÷[7× (45-40 )] In a formula, there are both small parentheses and middle parentheses. 在一个算式里，既有小括号，又有中括号，要先算小括号里面的，再算中括号里面的。 |
Powered by Discuz! X3.4
Copyright © 2001-2020, Tencent Cloud.
