Who Has More?: Comparing Decimals
Students will be able to compare like place value positions.
Introduction (10 minutes)
- Write "$1.75" and "$1.50" on the board.
- Ask students to determine which one is larger and how they know. Have them silently put up a finger when they are ready to discuss.
- Have students discuss in pairs.
- After a few minutes, have them share their thoughts as a whole group.
Explicit Instruction/Teacher Modeling (15 minutes)
- Write "753.126" on the board.
- Initiate a discussion with the students about how much the digits in each of the place values represents.
- Use the chart paper to create a visual model of the place values by writing the number above and writing out the place value name of each digit.
- Ask students how we would compare two numbers. (A possible answer could be: We compare the place value positions to see which number has the higher digit.)
- Write "862.578" across from the number above on the board, leaving a small space in the middle of the two.
- Pose the question, "Which number is larger?"
- Have students talk in pairs to figure it out.
- Discuss as a whole group, and allow students to share their ideas.
- Write the symbol <, >, or = in between the two numbers.
- Repeat if necessary.
- Let students know that they will be using this information to play a game.
Guided Practice/Interactive Modeling (30 minutes)
- Have the students get into pairs.
- Introduce students to the decimal cards and have them cut them out.
- Have students open their math journals to a blank page. This is where they will keep track of the decimals they compare while they play the game.
- Have students mix the cards up and distribute them equally.
- Students will keep the cards face down and turn them over at the same time.
- They will both write down both of the decimals leaving a slight space in between.
- They will work together to determine, using their understanding of place value, which decimal is larger.
- They will place a <, >, or = in between the two numbers in their notebooks.
- Whoever has the largest decimal will win and keep the both the cards.
- Students will continue like this until all the cards are gone.
- The player with the most cards is the winner.
- Students can keep playing new games until time is up.
- While students are playing, walk around the room and provide assistance when needed.
Independent Working Time (10 minutes)
- Distribute the Comparing Decimals worksheet and have students work on it independently.
- Enrichment Have advanced students also round the decimals to the nearest tenth.
- Support Pull struggling students into a small group and have them create their own place value chart to use while they play the game. Additionally, pair them with students who are at similar levels in their understanding of comparing decimals.
Assessment (5 minutes)
- Collect students' worksheets and review their answers to assess their understanding.
- Separate the students into groups based on what aspect of comparing decimals they are doing incorrectly.
- Meet with those students during the next day's activities to clear up any misconceptions.
Review and Closing (5 minutes)
- Have students self-assess their comfort with correctly comparing decimals.