Ext 6-8 Sampler

13 CONCEPTUALBASED INSTRUCTION 5 Step “We remember 10%ofwhat wehear, 30%ofwhat we see, and 90%ofwhat wedo.” —JeanPiaget Explicit InstructionUsingC–R–A RoundingLargeWholeNumbers Lessonsmove students through the3 stagesof learning: Concrete–Representational–Abstract Lesson2, 6ETeacherGuide 3 3 ©MathTeachersPress, Inc.,Reproduction by anymeans is strictly prohibited. Rounding to theNearestThousandUsing a“Halfway”Number The cost of a vacation tripwas $1,621. About howmuch did the trip cost? (to the nearest thousand) Build the number 1,621. Compare 1,621 to 1,000 and 2,000 by thinking of a “halfway” number. Complete the table to help round the numbers to the nearest thousand. 1,500 is halfway between 1,000 and 2,000. 1,621 ismore than the halfway number, so 1,621 rounds to __________. Build the two groups of thousands that 1,621 falls between. You can use base ten blocks and a “halfway” number to help round numbers. Number ComesBetween HalfwayNumber Rounds to 1. 1,362 and . . 1,362 rounds to . 2. 2,107 and . . 2,107 rounds to . 3. 5,720 and . . 5,720 rounds to .. 4. 7,942 and . . 7,942 rounds to . 5. 17,505 and . . 17,505 rounds to . 6. 48,496 and . . 48,496 rounds to . 1,000 2,000 1,500 1,000 7. Jaron’smother earned $38,225 last year.Howmuchmoney did she earn to the nearest thousand? _________ 9. The peak of Earth’s highest mountain, Mount Everest, is 29,029 ft.above sea level.What is this height to the nearest thousand? _________ 8. Lindsey earned $3,572 at her part- time job last year.Howmuch did she earn to the nearest thousand? _________ 10. Eli Manning threw for 4,933 yards during the 2011–2012 regular season. What is this number to the nearest thousand? _________ 11. Rounding is a skill used in estimating.What is the pattern for rounding a number to the nearest thousand?Give an example. 1,621 is between 1,000 and 2,000 2,000 000,4$ 000,83$ 29,000 ft. rebmun eht fI is less than the halfway number, the thousandsplace stays the same. If it is equal or greater than the halfway number, the thousands roundsupone. 5,000 yds 2,000 3,000 2,500 2,000 5,000 6,000 5,500 6,000 7,000 8,000 7,500 8,000 17,000 18,000 17,500 18,000 48,000 49,000 48,500 48,000 Objective3: To round largewholenumbers. Materials: Base tenblocks, playing cards Pattern for Rounding Each small groupof 4 to6 students shouldhave a small set of base tenblocks (20ones, 20 tens, and15hundreds). There shouldbe at least one thousandblock available for the activity. Writeon theboard: PopulationofBronx andBrooklyn,NewYork 1790 1850 1900 1950 Bronx 1781 8032 200,507 1,451,277 Brooklyn 4495 138,882 1,166,582 2,738,175 Round the1790populationof Bronx andBrooklyn to thenearest thousand. Ask eachgroup tobuild thenumber 1781. Howmany onesblocks? (1) Howmany tensblocks? (8) Howmany hundredsblocks? (7) Howmany thousandsblocks? (1) Thenumber1781 comesbetweenwhich twogroupsof 1000? (1000 and2000) Whatnumber ishalfwaybetween 1000and2000? (1500) Is it closer to1000or2000?How doyouknow? (It is closer to2000because itwouldonly take9ones, 1 ten, and2hundreds to equal 2000, but 7hundred, 8 tens and1onewouldhave tobe removed to get to1000.OR: It is closer to2000because1781 is greater than thehalfwaynumber 1500.) Ask eachgroup tobuild4495. (4 thousands blocks, 4 hundreds, 9 tens, 5ones.) Thenumber4495 comes betweenwhichgroupof thousands? (4000 and5000) Is it closer to4000or5000?Howdoyouknow? (It is closer to 4000because4495 is less than thehalfwaynumber 4500.) We canuse theseactivities todevelopageneral ruleor patternto roundanynumber toanyplacevalue.When youare rounding to thenearest thousand,what is the first thingyoudo? (Find thedigit in the thousands place.) What is thenext thingyoudo? (Look at thedigit to the right of the thousands place.) Howdoyouknowwhen to round thenumberup to thenext 1000? (when thedigit to the right is greater thanor equal to5) Whatdoyoudo if thedigit to the right of the thousandsplace is less than5? (The thousands placedigit remains the same and thedigits to the right of it become zero.) Use this rule to round the1850populationsofBronx andBrooklyn to thenearest thousand. (8032≈8,000 and 138,882≈139,000) Use the rule to round the1950populations to the nearestmillion. (1,000,000 and3,000,000) Read the information at the topof thepage.Ask a student to explain thepattern in their ownwords. RoundingRelays Divide the class intogroups of equal size.Give eachgroup adeckof 36 cards (tens and face cards removed).Thefirst player on each team turns over 4 cards and writes a4-digit number on theboard.The secondplayer on each team rounds thenumber to thenearest 1000. If the player rounds thenumber correctly, thenhe/she removes the4 cards from thedeck and turns over thenext 4 cards to form another 4-digit number for thenext player to round. If thenumber isnot rounded correctly, the cards are returned to thepilebefore theplayer selects fourmore cards.Thefirst team toget ridof their 36-carddeck is the winner. Skill Builders 3-1, 3-2 4.NBT.3 Concrete Representational Abstract Objectives fromCCSSandTEKSeditions for eachpageare indicated