Number Operation Activities - Grade 4

Zero - You're a Winner!

Purpose:

• To have children demonstrate and describe multiple strategies for determining differences to 10 000.

Number of students:

• 2

Materials:

• 3(4) dice
• paper and pencil for keeping track of the game

What you need to know before you start:

• The answer in a subtraction question is called the difference.
  
  Example: 12 - 5 = 7 (7 is the difference)
   
• Mental arithmetic strategies for subtracting will be very helpful in this game.
  
  Example: add on the difference 196 - 175 (185, 195, 196). The difference is 21.

Directions:

1. Player 1 writes 1000 at the top of a piece of paper.
2. Player 1 then rolls 1, 2, or 3 dice and arranges them as a 1, 2, or 3 digit number.
3. Player 1 then subtracts the number from 1000.
4. Player 2 now rolls the dice, arranges the dice to form a number, and subtracts the number from the previous difference.
5. Remember: You can roll 1, 2 or 3 dice to get your number.
6. Each player takes turns rolling the dice and subtracting their number from the previous difference.
7. The object of the game is to get to zero first. The player who reaches zero first is the winner.
8. If a player rolls a number that is greater than the remaining difference, the player loses a turn.

Part 2

• Play a few games using 3 dice and subtracting from 1000. Then try using 4 dice and subtract your number from 10 000.
• Remember: You don't have to use all 4 dice. You can use 1, 2, 3 or 4 dice to get your number. Plan your strategy so that you reach 0 first!