Computational estimation is being able to quickly and easily get a number that is close enough to the exact answer of a mathematical problem to be useful.

(definition from NZ Maths website) However, estimation is NOT using a calculator, working it out by hand, getting an exact answer or simply a guess!

Being able to quickly and easily get a number that is close to an exact number involves several mathematical skills. In our lesson about estimation, we are going to do the following activities:

Find out why we estimate and how much we do in real life.
1. Your teachers will make a list of all the ways they can think of that they use math in one week.
2. They will then categorize their list into two columns--estimation and exact, where the estimation column is math they only estimate and the exact column is where they figure out the exact answer to do whatever it is they are doing. (While they are doing that, you will, in pairs at your table, work on a concept of definition map.)
3. Teachers will then share that information and we will look at the "Did You Know?" page on this wiki.

We will then look at some instances of when we would want exact amounts:


You may have questions as you do this activity.Share those questions with Ms. Scot and she will add them to a list.

At your table, choose a person to go to Ms. Scot, if needed. Put the Runner "table tent" in front of this person. The runner takes questions to her to be listed.
Choose a person to be the timekeeper, who makes sure the group moves along and finishes in the allotted time. Put the Timekeeper "table tent " in front of this person.
Choose a person to be the arbitrator and make an arbitrary decision if there is disagreement. Put the Arbitrator "table tent " in front of this person.
Choose one person to glue the papers down. Put the Organizer "table tent " in front of this person. The Organizer gets no cards.
Choose one person to deal out the cards. Put the Dealer "table tent " in front of this person.
Chose two people to be the clean up folks. Put the Materials Manager "table tents" in front of these people. After the activity, these people will gather glue sticks, table tents concept of definition maps, and any other materials. Concept of definition maps go to Ms. Scot, all other materials are to be returned to Ms. White.

Files for teachers:



Each person looks at the two or three cards they have and decides whether they should estimate in that instance or find an exact answer.


The person to the left of the dealer goes first sharing only one of his/her cards and giving his/her opinion as to which column the card goes in. The group asks any questions, makes any comments, or holds discussion if needed. Then the Organizer glues it to the chosen column.

Examples are to be put into two columns: EXACT AMOUNT and ESTIMATION

Turn continues to the left, ONE card for each person at a time, repeatedly going around the table till all the cards are placed.

If there is tremendous discussion on a certain card, the timekeeper will call time after an appropriate amount of time, and then the arbitrator decides where the card goes. Circle any cards the arbitrator places.


EXAMPLES:
Adding cups of sugar in a cake recipe
Pouring how much milk into what size glass
Putting how much chocolate syrup on your sundae
Buying how much gas for the mower
Ordering how many pizzas for a class party
Filling up your Mom or Dad's windshield wiper cleaner
Sharing how many cookies with 5 friends
Ordering how many busses for a field trip
Saving how much money for holiday gifts for your family
Putting the pizza leftovers into how many baggies
Buying how many popsicle sticks for an engineering activity
Buying how many packs of beads for a craft necklace for a birthday party activity
Ordering how much paper for the school year (It comes in reams of 500 sheets)
Setting up how many chairs for graduation
Ordering how many certificates for PE awards
Filling out how many "Academic Excellence" certificates
Buying how much food for a camping trip
Planning how many bags of mulch for the flower garden
Budgeting how much money to buy an iPad
Buying how many seeds for a class gardening activity

After this activity, if we have time, we will discuss the concept of definition work.