K-4 MATHEMATICS STANDARDS

    WHOLE NUMBER OPERATIONS CONCEPT ACTIVITY

    Standard's bullets addressed by activity

    • develop meaning for the operations by modeling and discussing a rich variety of problem situations
    • relate the mathematical language and symbolism of operations to problem situations and informal language
    • recognize that a wide variety of problem structures can be represented by a single operation

    Materials needed

    • Base Ten Blocks

    Description of Activity

  • Group or classroom management practices

      • Students work in pairs or in small groups of three to four members.

    Using Base Ten Blocks or other manipulatives, show how you would solve each problem:

    Take Away

    • John has 96 baseball cards. He gave 32 cards to Paul. How many cards does he have now?
    • There were 978 people at a football game. Because of the heavy rain, 695 people left the game early. How many people braved the rain to continue watching the game?
    • Smelly found 24 snails for the picnic. Only 18 were eaten. How many were left?

    Comparison

    • Children have 20 teeth. Adults have 32 teeth. How many more teeth do adults have?
    • Kimo is 57 inches tall. Ginny is 42 inches tall. How much taller is Kimo than Ginny?
    • Last year 253 people attended the school carnival. This year 397 people attended the carnival. How many more people attended this year?

    Missing Addend

    • Pam had 27 children's books in her personal library. She gave many of these books away. She kept 10 children's books as these were her children's favorites. How many books did she give away?
    • Aleta had 75 cents. She bought bubble gum and got 20 cents change. How much did she spend for the gum?
    • Rico had 15 baseball caps. After giving his best friend, Kaukahi, some caps, he had 10 left. How many caps did Rico give Kaukahi?

    Suggested questions:

    • How are the take away, comparison, and missing addend problems different? How are they modeled with objects or pictures differently?
    • How do you know when to regroup and not to regroup?
    • Can you subtract from left to right? (e.g., start with tens column for two-digit numbers or start with hundreds column for three-digit numbers). Justify your answer.
  • Extensions

    • Students may make up their own problems for the class to solve.

    References

    Forsten, C. (1992). Teaching thinking and problem solving in math. New York: Scholastic Professional Books. pp. 40­41.

    Laycock, M. (1977). Base ten mathematics. Hayward, CA: Activity Resources Company, Inc. pp. 16­21.

    Smith, R. (1986). Word problems: Grade 2. Grand Rapids, MI: Instructional Fair, Inc. pp. 6­9.