Math Investigations

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Chapter 11

Part 1: Home and School Investigation

Choose a special day in the next month that the children can look forward to. It might be a holiday or a special event at school. Fill in the blanks indicating the special day and send the Letter to Family (PDF file) home with each child. The children will bring back two numbers. One number will indicate the number of days left in the month. The other number will indicate the number of days in next month until the special day. Ask, How could you use this information to find out how many days there are until the special day? In the discussion bring out the fact that adding the two numbers will tell you how many days there are until the special day. Ask the children to add their numbers and find out how many days there are until the special day.

You might want to put that number of small objects, such as beans, in a jar and pull one out each day so there are no beans left in the jar when you get to the special day. Do not forget to pull beans out of the jar for weekend days and school holidays.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 2 on estimating sums.


Introducing the Investigation

Tell children they are going to play a game in pairs. Show children the cards you have made from the Investigator Worksheet. Tell children that each child will draw two cards from the deck of cards. Each child will make a prediction about who will get the greatest number when the numbers in each set of two cards are added. Once they make their predictions, the children do the addition, check each other's addition, and then see who got the greatest number. Whoever predicted correctly scores a point.

Therefore in each round, both children could score a point, just one of the children could score a point, or neither of the children could score a point. Tell children to keep track of their score on a separate piece of paper by making a tally mark each time they predicted correctly.

Doing the Investigation

Watch children as they play the game. Make sure they understand how to play and are keeping track of the score.

After the children have played the game ask them to talk about how they made their predictions. Bring out in the discussion that estimation can help you predict.

Houghton Mifflin Math Grade 2