`EstimationIona Greenfield                Carnegie Elementary School                               1414 E. 61st Street                               Chicago IL 60637                               (312)535-0350             Objectives:     This lesson is designed for Kindergarten and First Grade.     Solve problems by guessing and checking.     Identify length by using informal units to estimate.     Guess the number of peas in a pod and write an addition and subtraction        sentence for the number of peas in the pod.       Materials Needed:     Construction paper    Ribbon        Peas      Scissors              Bubble gum    Scrap paper     Pencils               Blocks        Gummy bearsStrategy:          Students will draw around foot on construction paper to make foot prints.       Then they will cut them out.  Students will measure using informal units.      Students will cut a piece of ribbon to their approximate head size.  They      will check by using tape measure to compare actual size and approximate      size.      Guess the number of bubble gums in a jar.  Check by counting.          The students will guess the number of peas in a pod and write an addition      and subtraction sentence for the number of peas in a pod.  Check by using      counters (cubes or gummy bears). Conclusions:     These activities can be implemented to solve problems by guessing and      checking using non-standard units and standard units of measurement.  This      approach gives students hands on experience to solve problems. `