We have been working a lot lately on addition and subtraction facts, understanding their relationship, utilizing addition and subtraction to solve story problems, and using manipulatives and a 100's chart as tools to add and subtract.
One of my favorite parts about this time in first grade is that they are taking some of those foundational skills that we have been working on all year long and applying them to more difficult situations. Some examples include: Everyone is using our "facts of 10" and applying them to problems that equal 100, such as 3+7=10, therefore, 30+70 must equal 100! I loved that they so easily made that connection! They also have been studying all year how to count by 10's from any number on the 100's chart. They know that you go straight down. They also know that 34 has 3 groups of 10 in it. Therefore, to add 34 to any number, you can slide down 3 squares on the 100's chart and over 4 to find your answer. They also made the connection today that to add problems such as 20+45, you could simply break that into a mental math problem and do 20+40+5 and not use any manipulatives besides your brain! Love these connections!
One girl looked at a problem today. It was 22+34. She said, I don't even have to work that one out. I asked why? She said, "I already did 22+36 over here, so I know the sum will be 2 less because 34 is 2 less than 36. She is a great thinker!
Discovering these "alternate" ways of adding and subtracting helps make your child a more flexible thinker in math. Don't worry, I still show them and require them to learn the traditional algorithm, but they also know many other ways to approach problems. This will pay off for them in the long run. Being flexible in your thinking and working with numbers and have a strong sense of the number system will be crucial for success later on in math. And I have a class this year that LOVES to learn those "tricks"! They are so fun to teach. I can't wait for the rest of the year. With the foundation that we have been building all year, they are ready to fly!
