Estimating

Estimation is often referred to as making a smart guess. It is an important concept for children to begin to think about the way we use numbers in real life and the reasonableness of different quantities. We estimate quantities in our daily lives, whether it is at the grocery store, driving to work, or ordering off a menu. We should help our children develop this number sense through play and exploration, so they can make smart guesses throughout their own lives.

Throw Down

Materials: 20-30 small objects (beads, paperclips, counters, coins, etc.)

  1. Talk about what guessing means with your child.
  2. Tell your child that you will be guessing about how many objects are thrown down each time.
  3. Take some of the objects into your hands, and shake them up to build suspense.
  4. "Throw" the objects down, or place them gently on a surface.  
  5. Ask your child to quickly guess how many objects are there (1-3 seconds).
  6. Count together to see if the guess was reasonable or not. The goal is to have fun, not to always be correct.  A lot of learning happens when our guesses are way off, too!

Make it more challenging:

  • Use larger numbers (although it gets challenging to find enough objects)
  • Experiment with putting more or less space between objects when they are "thrown" down. Discuss any differences you notice in the guesses.
  • Let your child lead the game and test your guesses. Model some wild guesses, and ask your child if they are reasonable or not.

 

About How Many?

Materials: 20-50 small objects that are similar

  1. Spread objects on a flat surface.
  2. Ask, "About how many do you think there are?"
  3. Write down the estimate.
  4. Say, "Now let's count the objects and see how close we got to our estimate!"
  5. Count together and write down the actual number.
  6. Discuss your findings together.

Make it more challenging:

  • Place objects in different containers before asking child to estimate.  Discuss how the different sized containers influence the estimate.
  • Give your child some options 20, 50, 100, 500, 1,000.  Ask, "Which number do you think is closest to the actual amount?"

 

How Many Windows?

Materials: buildings to look at in real life or pictures of different buildings

  1. Talk about different buildings and their designs.
  2. Ask, "About how many windows do you think are in that building?"
  3. Focus on the strategies that your child uses to estimate or find the actual answer.
  4. Encourage child to explain thinking and to find different ways to solve the problem. (Ex. counting rows, finding a group of ten and estimating how many groups of ten)

Make it more challenging:

  • Try this with irregular buildings or very large buildings.
  • Take a picture of the building and let your child write about the experience.
  • Pick a number and ask your child to draw a building with that many windows.