We are learning more addition and subtraction mental math strategies!! We have been reviewing the 15 we have learned up until this week! We had sent home a package including all of these previously, but also posted below for reference. Please use these at home to help with our math work that comes home and to practice these strategies when you get a chance to build our skills of our math facts!
'Seeing' these strategies in various number sentences (equations) show students understand the concepts of addition and subtraction with all the daily practice we do with this concept. Number sentences are very abstract but we have been learning what they mean all school year. The important part here is that these strategies are little 'tricks' to help us quickly solve addition and subtraction problems with smaller numbers. They are to be mental math and while the strategies are becoming more complex, we do want to be able to see them, name them and use them with efficiently rather than using materials. These strategies can also be applied to larger numbers and that will be built on in the next school year as the expectations do build on previous year's learning.
The past week, we have been introduced to a new subtraction strategy called Reverse Doubles. This is a very special Think Addition strategy we worked on previously, where we use the inverse relationship between those tricky subtraction sentences and turn them into addition sentences as part of our Fact Family learning. Reverse Doubles are those special doubles addition facts that we can automatically recognize that inverse relationship when applied to their subtraction counterparts! We have been really focusing on doubles lately with our strategies and how they can quickly help us with several different math facts (doubles, monkey in the middle, doubles plus one, reverse doubles).
After the long weekend, we will focus on a new addition strategy called Bridge to Ten. This strategy is one that will begin to help us break numbers apart and manipulate them to make adding numbers mentally easier. If we know our Make 10 facts, that we have been practicing all year, this one is the next step to apply to leap over a group of ten. This will come in handy especially for larger numbers after lots of practice!
Count On and Count Back are really if no other strategy is available but still need a plan B! We will use Count On and Count Back more and more as we explore larger numbers and able to use various materials to help us.
We continue to focus on one strategy per week but sometimes we spend two weeks if we need some extra time with learning these new concepts. Then we will review all strategies on Thursday and then on Fridays we will have our 5 question quiz to see how we are doing as we continue to learn and apply these strategies.
We are becoming math whizzes!!
