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Mathematics Enhanced Scope and Sequence ­ Grade Four

Rounding Decimals

Reporting category Overview Related Standard of Learning Objective

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Number and Number Sense Students round numbers to the nearest whole number, tenth, and hundredth. 4.4b

The student will round numbers to the nearest whole number, tenth, and hundredth.

Prerequisite Understandings/Knowledge/Skills · Students must know how to use both base-10 blocks and decimal grids to create models of given numbers. · Students must know how to read and write numbers with decimals up to the thousandths. Materials needed

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Base-10 blocks: large cube (thousands), flats (hundreds), rods (tens), units (ones) Decimal grids (See the "Reading and Writing Decimals" activity above.) Decimal cards (See the "Reading and Writing Decimals" activity above.)

Instructional activity 1. Have students begin by creating base-10 models or decimal grids of some numbers containing decimals. Have students use the models or pictures to tell what whole number, what tenth, and what hundredth the decimal is closest to. You may need to review place value and writing decimals. Have students write out the decimal they created and again tell what whole number, what tenth, and what hundredth the decimal is closest to. Have students use the pictures or models to help them remember the rules of rounding. Use the decimal cards, if you wish, to have students randomly choose decimals to round to the given place. If students are still having difficulty with rounding, refer to SOL 4.2 for more ideas. A picture of a rounding mountain also helps some students. Locate the desired number on the mountain. If it lands on a slope, it will fall down to the nearest number. If it lands exactly on the top, it will roll over to the right side. 0.015 0.010 0.020 0.025 0.030 0.035 0.040 0.045 0.050

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Sample assessment

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Have students round numbers to the nearest whole, tenth, and hundredth.

Specific options for differentiating this lesson Technology

Virginia Department of Education 2004

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Mathematics Enhanced Scope and Sequence ­ Grade Four

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Provide students with a visual strategy or model to remember how to round to the nearest whole number. Have students use a highlighter to highlight the number in the tenths or hundredths place to assist with rounding. Have students use a paint software program to create visual representations of decimals on the tenths, hundredths, and thousandths grids. Have students use a visual strategy such as circling the targeted place value to assist with rounding. Provide students with a cardboard frame to frame the targeted place value. Have students use individual place value mats to assist with rounding activities (each place is coded with a different color and the students use number cards).

Multisensory · Have students use a math jingle or rap to remember how to round to the nearest whole number, tenth, or hundredth. · Have students act out one of the visual strategies to remember how to round to the nearest whole number (e.g., mountain strategy). · Have students use decimal cards with numbers written with puffy paint, sand, glitter, etc., in different colors to highlight the targeted place values when practicing rounding. Community Connections · Invite a contractor to the class to discuss how to estimate materials and/or cost for new construction. · Take a field trip to a home improvement store to plan the cost for a classroom project. Small Group Learning · Have students work in pairs or small groups to plan a classroom building project complete with estimated costs and material needs. · Have students work in small groups using the individual place value mats to solve assigned problems. · Have students in pairs to create a model of the mountain strategy. Vocabulary · Students must know the following vocabulary: estimate, round, hundredth, tenth, model, and whole number. · Have students build an individual or class math glossary with definitions and pictorial and/or numerical representations. · Have students use a software drawing program to create a visual representation of the process of rounding. · Have students create an individual or class math dictionary. Each page is divided into four equal sections labeled: word, illustration, definition, and real-world use. Students complete each section of the page as it relates to the given math term. A template can be created in a word processing program for some students to sue. · Use a class word wall to reinforce the vocabulary. · Have students complete a cloze activity to review math vocabulary introduced to this point in the curriculum. Student Organization of Content · Have students turn their notebook paper sideways to create vertical lines for writing numbers including decimals.

Virginia Department of Education 2004 2

Mathematics Enhanced Scope and Sequence ­ Grade Four

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Have students create a visual cue for rounding whole numbers for individual reference on their desks (use Velcro). Provide students with a visual list of steps to follow when rounding to the nearest whole number, tenth, and hundredth.

Sample resources http://standards.nctm.org/document/chapter5/numb.htm#bp1 ­ NCTM Principles and Standards for School Mathematics chapter on the Number and Operations Standard for Grades 3­5. http://funbrain.com/football/index.html ­ Power Football provides interactive practice with the decimal concepts. http://askeric.org/cgi-bin/printlessons.cgi/Virtual/Lessons/Mathematics/Number_Sense/NUS0200.html An activity in which students physically arrange themselves into decimal numbers, this lesson can be used to assess students' understanding about decimals. Thinking Rationally about Fractions, Decimals, and Percent: Instructional Activities for Grades 4 through 8 ­ Lesson plans available from VDOE at http://www.pen.k12.va.us/VDOE/Instruction/Math/FractionsDecimalsPercent.pdf.

Virginia Department of Education 2004

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Mathematics Enhanced Scope and Sequence ­ Grade Four

Released SOL test items

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Last week Drew worked 7.9 hours. This week he worked 8.6 hours. How many more hours did he work this week than last week? F G H J 1.7 1.3 0.7 _ 0.3

14 Which is read "fifty-five and twenty-one thousandths"? F G H J 5,521,000 55,210 55.21 55.021

Virginia Department of Education 2004

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Mathematics Enhanced Scope and Sequence ­ Grade Four

17 What digit goes in the space to make the number sentence below true? 1.6238 < 1._017 A B C D 4 5 6 7

13 A piece of wood is 2.27 centimeters thick. What is that measurement rounded to the nearest tenth of a centimeter? A B C D 2.1 2.2 2.3 _ 2.5

Virginia Department of Education 2004

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Mathematics Enhanced Scope and Sequence ­ Grade Four

A box of cherries weighs 3.082 pounds. What is that rounded to the nearest hundredth of a pound? F G H J 3.0 pounds 3.1 pounds 3.09 pounds 3.08 pounds

Which is true? F G H J 1.0254 > 1.24 1.1763 > 1.199 1.978 > 1.8979 1.3046 > 1.3106

Virginia Department of Education 2004

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Mathematics Enhanced Scope and Sequence ­ Grade Four

Virginia Department of Education 2004

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Rounding Decimals

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