Dueling Decimals
Adapted from AIMS LESSON
Standard:b. Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.
EQ: How do I compare decimal numbers?
Materials: index cards, scissors, markers, colored pencils, paper bags, decimal wheels
Management:
1. This activity can be done in pairs or in groups offour with two students using each bag.
2. Numbers can be drawn and used just once, or theycan be drawn and put back in the paper bag.
3. Run the decimal wheels on two bright colors ofcardstock. Each student will need one wheel ofeach color.
4. This activity is easily adaptable to comparisonsof thousandths by just having students write numberson their cards in tenths, hundredths, andthousandths.
5. If students have never used decimal wheels, youmay want to spend some time acquainting studentswith how they work. Begin by having themtake note of the number of sectors in the wheel[10]. Discuss how each sector can be representedas a fraction (1/10) or as a decimal (0.1). Invitestudents to dial and show 0.1 in one of the colors.
Ask what the other color represents [0.9]. Continuewith several examples, including things suchas “If the wheel represents one dollar, show methe value of three dimes in one color.” Then askstudents to represent the value of a quarter. Discusswhat they had to think about. [The quarter’svalue comes halfway between two tenths andthree tenths.] This should help students to understandthe hundredths place as represented on thewheels. The tenths are divided into ten tick marks;a tenth of a tenth is a hundredth.
Procedure:
1. Each student gets 5 index cards and one paper bag. Students need to cut cards in half to make 10 cards.
2. Have students write any 10 decimals they want,using tenths and hundredths.
3. Tell them to place their decimal cards into the bag.
4. Pass out decimal wheels. Teach students how to cut on the dotted line and slide the two together. Practice a few together.
5. Students will now have a dueling contest. Each student will draw one card from the bag and compare values. They will use their decimal wheel to show the decimal value.
6. Students need to record both decimal values and use the correct symbol.
7. For each duel they will need to color the wheel on paper to prove which one is more or less.
Dueling Decimal Recording Sheet
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Dueling Decimal Recording Sheet
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Cut and put together big decimal wheels