This free math tutoring video explains the three ways of thinking about subtraction (taking away, finding the difference, and whole/parts) and explains which one is best and why. I also talk briefly about why counting strategies are not as effective as visualization of quantities. There will be more on this topic in a later video.
Once again, Cuisenaire Rods come to the rescue and make everything easy. They are a treasure. If you don’t yet have some, go buy them!!!
This free math tutoring video shows me introducing my 4-year-old (and “Wormie the Snake”) to subtraction using Cuisenaire Rods. Just see what piece is missing! Cuisenaire Rods make it all so easy!
Here’s another free math tutoring video showing an activity you can do with young kids. If you know the doubles facts, you can find the doubles +/- facts by using logic. You can also do this activity with countable objects – Skittles, for instance. You have 4 Skittles and the child has 4 Skittles. Ask the child how many Skittles you both have in all. Then give a Skittle to the child and ask how many you each have. Talk through the logic of what happens when one person shares with another. Do how many more do you have? How many less do I have? Do we still have the same amount altogether?
If you watch carefully in this video, you’ll be able to tell that my 4-year-old isn’t fully understanding the logic of this. It should be more clear to her in 6 months to a year, I think. This is a good Kindergarten and 1st grade skill to learn. Do it with numbers other than four, too!