Rounding+and+Estimation



(10 problems) (14 problems)

[|Rounding and Estimation Common Assessment.docx]

**TEKS:**
 * 3.5A** round whole numbers to the nearest ten or hundred **3.5B** use strategies including rounding to estimate solutions to addition and subtraction problems


 * REQUIRED LESSON: This lesson needs to be included some time this week.**

[|Addition and Subtraction.pdf]

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**1.** Ask students to think of things that are round. Examples may include wheels, donuts, tires, cookies, etc… **2.** Show students a premade number line and ask them which numbers on the number line they would consider to be “round” numbers. Students usually think of numbers that end with zero as being “round” numbers. **3.** Students will make their own number lines using Handout 2. **4.** Have students highlight or color the same color all of the numbers that end with a zero on their number lines. **5.** Explain to students that you can round numbers to the nearest ten to tell about how much or how many. Give real world examples: **When someone asks about how much you spent on a video game, instead of saying you spent $49.99, you might say you spent about $50. ...or... If you are going to a baseball game and need money for a coke, peanuts, and a souvenir, you might say you need about $20 instead of trying to add up exactly how much each items costs.** ======

**6.** Guide students to think of other times they might not need a precise answer and would use rounding. Many of their examples will involve money.
 * 7.** Using their new number lines, students will round numbers. The teacher calls out a number and the students locate it on the number line. The students look to see which “round” numbers are on either side of the number called. Student must determine which “round” number is closer to the number called. Remember that if the number is exactly halfway between the two tens, mathematicians always round to the greater number. Do this for several numbers, checking for understanding as you go.
 * 8.** Students complete the “Let’s Practice Rounding” worksheet with teacher as a Guided Practice. The last two questions on the sheet could be answered in the student’s Math Journal.


 * Day 2:**
 * 1.** The teacher will show how she turned the number line from yesterday’s lesson into a rollercoaster. Ask the students what they notice about the rollercoaster.
 * The “round” numbers are at the lowest points.**
 * The numbers ending in “5” are at the highest points.**


 * 2.** Point out that when rounding the student must find which two round numbers his/her number comes between. In other words, which hill of the roller coaster is his/her number on.
 * 3.** When they find the correct hill, or correct “round” numbers, guide them to see that if the rollercoaster were to stop on their number and their number ends in 1, 2, 3, or 4 it will roll back down to the lower “round” number. If the rollercoaster were to stop on their number and their number ended in 6, 7. 8 or 9 then it would roll forward to the larger “round” number.
 * 4.** Have students brainstorm what would happen if the roller coaster stopped on a number ending in 5, right in the middle. Guide them to understand that we would need to push the rollercoaster over the top down to the larger number.
 * 5.** Have the students practice using this method of rounding.
 * 6.** Ask students what they think they would need to do if the numbers were larger, like hundreds numbers. Guide students to see how the process for rounding numbers to the nearest hundred is similar to rounding numbers to the nearest ten. The only difference is that they must find the two “round” hundreds numbers on either side of their number and then look at the number in the tens place to see which way to go, up or down.
 * 7.** Practice rounding to the nearest hundred using the rollercoaster method. **Practice, practice, practice!**[[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Rockets+10.pdf"]] [|Rounding Rockets 10.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10.pdf"]] [|Rounding Nearest 10.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+Again.pdf"]] [|Rounding Nearest 10 Again.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+MC.pdf"]] [|Rounding Nearest 10 MC.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+Numberline.pdf"]] [|Rounding Nearest 10 Numberline.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+Numberline+2.pdf"]] [|Rounding Nearest 10 Numberline 2.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+Chart.pdf"]] [|Rounding Nearest 10 Chart.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Robots+100.pdf"]] [|Rounding Robots 100.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+100.pdf"]] [|Rounding Nearest 100.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+100+Again.pdf"]] [|Rounding Nearest 100 Again.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+100+MC.pdf"]] [|Rounding Nearest 100 MC.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+100+Numberline.pdf"]] [|Rounding Nearest 100 Numberline.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+100+Chart.pdf"]] [|Rounding Nearest 100 Chart.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+and+100.pdf"]] [|Rounding Nearest 10 and 100.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+10+and+100+Again.pdf"]] [|Rounding Nearest 10 and 100 Again.pdf][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+Nearest+Dollar.pdf"]] [|Rounding Nearest Dollar.pdf]
 * Day 3:**
 * 1.** Review rounding to the nearest hundred from the day before.
 * 2.** Today students will use compatible or “friendly” numbers to solve problems.
 * 3.** Explain to students that it is easier to use numbers like 100, 500 and/or 800 instead of the numbers 94, 517, and/or 762 when estimating sums or differences.
 * 4.** Remind students of the conversation from the day before where you discussed how there were times when it was not necessary to have an exact answer, these are the times when it is acceptable to round the numbers in the problem and get an “estimate” of the answer instead.
 * 5.** Here is a power point with word problems that use estimation. [[image:http://www.wikispaces.com/i/mime/32/application/vnd.ms-powerpoint.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Estimation+Problem+Solving.ppt"]] [|Estimation Problem Solving.ppt] Work through several of the problems with the students as guided practice. Estimation problems are asked in a similar way but the answer choices vary greatly. All of the possible answer choices are represented in the power point so choose carefully and try to get some of each type.
 * Day 4:**
 * 1.** Continue with more problems from yesterday’s power point.
 * 2.** Students will complete an Independent Practice Sheet of word problems that require the use of estimation.
 * Day 5: Review and test!**[[image:http://www.wikispaces.com/i/mime/32/application/vnd.openxmlformats-officedocument.wordprocessingml.document.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+and+Estimating+Practice+Problems+without+answer+choices.pdf.docx"]] [|Rounding and Estimating Practice Problems without answer choices.pdf.docx][[image:http://www.wikispaces.com/i/mime/32/application/vnd.ms-powerpoint.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Estimation+Problem+Solving+without+answer+choices.ppt"]] [|Estimation Problem Solving without answer choices.ppt][[image:http://www.wikispaces.com/i/mime/32/application/pdf.png width="32" height="32" link="http://tves3rdgrademath.wikispaces.com/file/view/Rounding+and+Estimating.pdf"]] [|Rounding and Estimating.pdf]