Unit 6 Picking Day - mixed operation 采摘节——混合运算 Lesson 1 There are sixty baskets. 一共有60只篮子。 We came in 18 seconds, each with three baskets. 我们来了18秒，每家分3只篮子。 There were 48 people on the bus. 这辆大巴车上共有48人。 There were two minibuses behind it, there are 26 people in each car. 后面还有两辆中巴车，每辆车上有26人。 What questions can you ask? 你能提出什么问题？ Cooperative exploration 合作探索 1. How many baskets are left? 1. 还剩几只篮子? Subtract the divided number from the total number. 用总只数减去已分的只数。 If you know the total number, you have to figure out the number that you have divided. 总只数知道了要先求已分的只数。 eighteen times three is fifty- four 18×3＝54(只) sixty minus five is six 60－54＝6(只) It can be calculated by a comprehensive formula. Can you do it? 可以列综合算式计算。你会算吗？ First calculate eighteen times three is fifty four,then sixty minus fifty four 60－18×3 2. How many people were in the three cars? 1. 3辆车一共乘坐了多少人？ Think about it. What comes first when there are addition (subtraction) and multiplication in a formula? 想一想，在一个算式中既有加(减)法，又有乘法，应先算什么？ Lesson 2 I can pick 12 boxes of grapes. 我摘的葡萄可以摘12箱。 I picked 35 kilos. 我摘了35千克。 I picked 45 kilograms. 我摘了45千克。 What questions can you ask? 你能提出什么问题？ Cooperative exploration 合作探索 1. How many more boxes of grapes did Mom pick than Yang Yang? 1. 妈妈比杨阳多摘了多少箱葡萄? Take what Mom picked and subtract what Yang Yang picked. 用妈妈摘的减去杨阳摘的。 Mother picked already know, to ask Yang Yang picked how many boxes. 妈妈摘的已经知道了，要先求杨阳摘了多少箱。 Thirty divided by five is seven (carton) 35÷5＝7(箱) Twelve minus seven is five(carton) 12－7＝5(箱) You can write the comprehensive formula. What should come first? 可以列综合算式。应该先算什么？ 2. How many cartons of grapes did Mom and Dad pick? 1. 妈妈和爸爸一共摘了多少箱葡萄？ Think about it. What comes first when there are addition (subtraction) and multiplication in a formula? 想一想，在一个算式中既有加(减)法，又有乘法，应先算什么？ Lesson 3 A basket of apples is thirty-eight less than a basket of apples. 一篮苹果比一筐苹果少38个。 I picked 43 pears. 我摘了43个梨。 I have picked 21 more pears than you. 我摘的梨比你多21个。 What questions can you ask? 你能提出什么问题？ Cooperative exploration 合作探索 1.How many apples are there in three baskets? 1. 3篮苹果一共多少个？ So let's figure out how many apples are in each basket, and then how many apples are in three baskets. 先算每篮苹果多少个，再算3篮苹果多少个。 Sixty minus thirty eight is twenty two 60－38＝22(个) Twenty two times three is sixty six 22×3＝66(个) If I write it as one formula, how do I write it? 如果写成一个算式，怎样写呢？ If it is written as one formula, parentheses should be used. 如果写成一个算式，应该使用小括号。 Think about it, there are parentheses in the formula, what should be calculate first? 想一想，算式里有小括号的，应先算什么？ 2. How many boxes of pears can Dad pick? 1. 爸爸摘的梨能装几盒？ Calculate dad picked how many pears first, then calculate...... 先算爸爸摘了多少个梨，再算...... Let me do the comprehensive formula. 我列综合算式计算。 Can you calculate the following problems? 1. 你会计算下面各题吗？ Can you summarize the order of mixed operations? 你能总结出混合运算的运算顺序吗？ In the equation without parentheses...... 在没有括号的算式里...... In the equation with brackets...... 在有括号的算式里...... |
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