## Thursday, August 7, 2014

When: in class time or extra time around school
Where: at school
Why: to accompany lessons on adding and subtracting
What will we use: cards (playing cards or number cards), dice, possibly some packaged games

These are ideas for enrichment and deepening activities, to be discussed with the teacher. Do you have any thoughts on which are the best games? Please comment below.

Future posts will repeat this exercise looking for activities that support time+calendar work and another around money.

Games
(1) Blackjack:
Game A: Use number cards instead of playing cards, no double down
Game B: With playing cards, can use simplified traditional rules (no double-down).
Game C: To focus on adding by a particular number, redefine the face cards to that value, e.g., 9, to make the frequent additions more challenging.

Note:  B or C can be modified to fix the value of ace as 1 instead of allowing the 1 or 11 option.

(2) 21 (as with blackjack, these can be played with traditional playing cards or number cards)
Game A: deal out n cards to all players (n should be between 4 and 7, depending on number of players). Players take turns putting down a card and adding to the sum until the next player can't stay under 21. The last player to play collects the cards which have been played.  Count number of cards played at the end as points.

Game B: Same as A, but each player can add or subtract the value of your card from the accumulating value of the pile. The value of the pile has no bounds and gets collected by the player to land exactly on 21.

Game C: modify the value of the face cards (if using traditional playing cards).

(3) Strike it out: described on this NRICH site and blogged about here

(4) Number bonds of multiples of 5

For those who don't know Sum Swamp, players roll three dice, two with number values and one with addition/subtraction operators. They perform the indicated calculation and move that number of spaces along a path toward the finish line. In other words, it is chutes and ladders, but with the operation die added.

Game A: play with 2d6
Game B: play with other pairs of dice. I think Sum Swamp will work up to 2d10, but the path is probably too short for larger dice. Chutes and Ladders can probably work up to 2d20, but I would impose a rule that the winning player has to land exactly on the final square (or maybe within 5?)

(6) Dotty Six
Game A: describe on this NRICH page
Game B: change the target to complete each box to 10 and use tally marks instead of dots
Game C: change the target to another higher number (I suggest either 15 or 20) and use tally marks.

(7) Pass the peas, again, NRICH
Though the kids will probably end up throwing dried food at each other?
Game A: as described
Game B: use 2 dice and then multiply the die value with the value of the number square it lands on, then subtract those from your residual figure.

(8) Subtraction squares

Challenges
(1) Eggs in a basket: NRICH
(2) 5 steps to 50: NRICH. Their version only uses 10s and 1s, but the step sizes can be changed. Also, they don't specify what dice to use, so I would prefer 2d10 to get 0 to 99 as the range of starting values. I made a pencilcode program to explore this (here) but now see that I missed the point about using dice to start, so maybe an interesting constraint is formed by using 2d6?

Investigations