## Thursday, 16 October 2014

This one is pretty simple but the students seem to really like it. We got the idea from a colleague and am sure we aren't the first to do it. Basically you get groups of three. Two students grab a card from a deck and without looking at them put them on their foreheads facing out. The third student multiplies the two numbers and states the product. Those holding the cards then try to guess the two numbers.

• Gr8NS - represent the multiplication and division of integers, using a variety of tools
• MPM1D - As review
• MFM1P - As review

• All that is needed are decks of cards. Here black cards are positive and red cards are negative (or vise versa if you prefer). You may wish to remove the face cards or come up with protocol for which numbers the face cards represent. On side note, if you use the face cards, don't assume that all students will know what a face card is (ie a card that literally has a face on it) as it seems that more and more students may not have the experience of playing cards at home.
• Optional materials might be a personal portable white board and dry erase marker for students.

1. Create groups of three students.
2. In the group choose 2 mind readers and one product leader
3. Each mind reader chooses a card and without looking at either card, place them face out on their foreheads.
4. The product leader multiplies the two integers (red is negative, black is positive) and states the product (or writes it on their whiteboard)
5. The mind readers then take turns guessing the factors (cards) they are holding).
6. The first to guess correctly becomes the new product leader and the original product leader becomes a mind reader.
7. Repeat as often as you wish

• Integer Mind Reader Instructions (pdf)
Did you use this activity? Do you have a way to make it better? If so tell us in the comment section. Thanks