Game: Greatest Of All Thieves (Estimating and subitising)

SUBJECTS:  Maths
YEARS:  F–2, 3–4

Gasp! The goat burglars robbed the piggy bank and stole all the pig's money! 

As a team, use subitising to estimate how big the heist is and recover the fortune from those greedy goats. Then, use number sentences to explain your thinking.

Mathematical ideas and strategies this game supports:

• Estimate the total of a collection using subitising.
• Place value.
• Calculate a total using addition and/or multiplication facts (with arrays).
• Use number sentences to explain your thinking.

How to play

This launch activity does not use scoring or points.

1. 1.The teacher chooses a level to play.
   • Level 1 uses numbers 8–30 and coins.
   •  Level 2 uses numbers 31–1,000 and $1, $10 and $100 values.
2. 2.Three goats rob a piggy bank filled with money. The class must estimate how much money was taken. In Level 1, they have 2 seconds to look at the collection of stolen coins. In Level 2, they have 3 seconds to estimate the total value of money stolen. When they have discussed it as a group, they enter their estimate in the text box.
3. 3.The three goats each arrange their collection in a different way, and the class may look at these arrangements for the next step.
4. 4.The students work together to use either addition or multiplication facts to count the collections. They discuss which way they think is the most efficient way for them. They might also have ideas for other ways to arrange the items to count them. By now the class will have a sense of whether their estimation was close.
5. 5.The calculation is entered. The students find out if they counted correctly and how close their estimate was.
6. 6.In Level 1, a series of discussion slides are presented that can be used by the teacher to discuss various number sentences for each collection. There are no discussion slides for Level 2.

Copyright 

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