EstimatingDistances（估算距離）

1、 HYPERLINK l _Estimating_Distances 英文版估算距離設(shè)計(jì)者：Chad Dahl學(xué)生級(jí)別：2，3科目：數(shù)學(xué)/測量序言：“看地圖”并非僅僅是看著地圖，找出你在地圖上的位置；有時(shí)，為了搞清從甲地到在乙地需要花費(fèi)的時(shí)間，你不得不在地圖上估算出兩地的距離。很久以前，人類就學(xué)會(huì)了估算距離的方法。設(shè)計(jì)本節(jié)課的目的是為了讓學(xué)生們知道一些估算距離的方法，活學(xué)活用數(shù)學(xué)知識(shí)。教學(xué)目標(biāo)：使學(xué)生們利用教師示范的方法來估算一段較短的距離；讓學(xué)生們發(fā)明出另一種估算距離的方法。背景資料：這節(jié)課最好在教室外進(jìn)行；如果把學(xué)生分成小組進(jìn)行活動(dòng)，效果會(huì)更好；應(yīng)先從較短距離開始，逐漸過渡到較長的距離。教

2、學(xué)材料：尺子；鉛筆；卷尺；紙；粉筆教學(xué)過程：向?qū)W生提問：從他們站立的地方到教師所指的某物的距離是多少？告訴學(xué)生，可以用腳步來測量距離；劃一條線，讓學(xué)生們站在線的后邊，以正常的步幅走出兩步；用尺子丈量從線條到學(xué)生腳后跟之間的距離；分別把這些代表距離的數(shù)字除以2，就是每個(gè)學(xué)生邁出一步所走過的距離，把它們在紙上記錄下來；讓學(xué)生們數(shù)一數(shù)：從自己站立的地方走到教師先前指定的某物處，一共走了多少步？記下自己的步數(shù)，再把它與表示自己步幅的數(shù)字相乘，即得出結(jié)果。例如，約翰每走一步是3英尺，他走到目標(biāo)物所在地點(diǎn)，一共走了16步，那么，163=48，約離目標(biāo)物的距離是48英尺；再讓學(xué)生估算從站立點(diǎn)到另一目標(biāo)物的距

3、離；問學(xué)生：為什么這種估算距離的方法很重要？教學(xué)評(píng)估：在活動(dòng)開始前，選定一段距離，并用卷尺量出這段距離的實(shí)際尺寸，然后讓學(xué)生們進(jìn)行估算，看看結(jié)果是否一致；讓學(xué)生們想出另一種估算距離的方法來。HYPERLINK l 估算距離Chinese versionEstimating Distances An AskERIC Lesson Plan Submitted by: Chad DahlEndorsed by: Don Descy, Mankato State University Date: May 14, 1997 Grade Level(s): 2, 3 Subject(s): Mathem

4、atics/Measurement Description: Map reading is more than just looking at maps and finding where you are on the map. Sometimes you have to estimate a certain distance on a map in order to know how long it will take to get from point A to point B. Estimating distances has been with us for a long time.

5、Students should know some methods in estimating distances and use math as a real use. Goals: The students will get a better understanding on how people estimate distances and the process in estimating short distances. Objectives:1. The students will be able to estimate a short distance by using the

6、method I demonstrate to them.2. The students will invent another method in estimating distances. Background Information: This activity is best used outside. Small groups would be better than the whole class at once. Start out with short distances and then with longer distances. Concepts: Students wi

7、ll be able to perform algebraic problems while estimating distances. Materials:measuring stick pencil tape measure paper chalk Procedure: 1. Ask the students what they think a certain distance is between where they stand at and the object you point out. 2. Tell the students there is a way to estimat

8、e distances by their own pace count. 3. Have the students stand behind a line and have them take 2 normal steps. 4. Measure the line to the heel of the student with the yard stick. 5. Then divide that number by 2 and write it down on a sheet of paper. This will be the students average pace count. 6.

9、 Have the students count the number of paces it takes to get to the certain object. 7. Take that number and multiply it by the students pace count. For instance: Johns pace count is 3 feet. It took 16 paces for John to reach the certain object. 16 paces multiplied by 3 feet = 48 feet for an estimated distance. 8. Repeat the steps with another object. 9. Ask the students why they think this would be important. Assessment: Pick the a distance and measure before the a