Today I learnt about subitizing through the dice problem. Subitizing is "instantly seeing how many." And to learn to subitize children need a lot of exposure and scaffolding. They need to be given a lot of opportunities and variations. Guessing the number of fruits in the bag without counting seems like an interesting idea.
For the dice problem, after looking at all sides of one of the die, I was able to visualize the missing number. I did the same with the other die and was able to derive the answer to the problem. My partner who knew that the opposite sides of the die add up to 7 had her own method of coming up with the answer. My classmates shared another method which I felt was a bit long winded. To individually subtract the numbers seen from 21 as all sides of the die add up to that number.
And to solve problems like these children need to have number sense, be able to recognize patterns and generalize and use their metacognition.
I thought this would be an interesting way of subitizing for children. With the dots arranged in this way, would it be easier for the children to subitize?