Lesson in estimating….

Emma had an orthodontic appointment yesterday and every month they have a game.  We are new to the office so have only witnessed two games and both have required Emma to estimate numbers.  The first she needed to guess how old each of the employees were (based on pictures on a board) and add them all together using a calculator.  Age estimating is not something I expect her to be able to do or that I think I can teach her!  This month they had a jar full of mini marshmallows and wanted a guess to how many were in there!

So Emma looked at the jar and I asked her if she remembered how many 10s were in 100 which she replied 10 to.   Then she guess 120 marshmallows.  When I realized the contest would still be going on during her next appointment I kind of joked we should go home and see what 120 marshmallows looked like so she could see if she should guess higher or lower at the next appointment.  The Tech seemed to think that was a great idea!

So we bought a bag of marshmallows at the store and I glanced at the stores canning jars and I think they were using a quart size jar.  So today we set out counting marshmallows. 

First Emma counted 120 (in groups of ten and recorded them using tally marks).  When she was done, she turned to me and said “I think there are more than 120 in the jar!”

Second, I looked though containers I had and found one that was 32 oz.  Filled it up with marshmallows and Emma counted those and this time had me make tally marks.  There were 200 in the 32 oz.  I told her that I thought the jar they used would hold 2 of the 32 oz jars and her eyes lit up and she said “I think I will guess 400 next time!”

Smart girl!

 

The bowl on the left is the bowl holding her guess of 120.  She is in the process of counting how many were in the 32 oz container.

 

 

 

 

 

 

Maybe it is sort of cheating but she is learning a great lesson on estimating and learning how many of something might fit in containers.  This is actually something I have been thinking of doing for a fun activity for a while after seeing a guessing contest for gum balls.