Strategic Mathematical Thinkers

We have been learning how to be more strategic mathematical thinkers.  This week we learned how we can make +9 problems into +10 problems so we can solve them in our heads.  For example, if I see the math problem 3+9, I can picture the 9 taking 1 away from the 3 to make the math problem 2+10.  +10 problems are much easier and quicker to add in our heads!

We have been working hard on memorizing our doubles facts.  We love to practice memorizing these facts with the doubles rap song.

 

We have been doing this rap for a while.  So now that we know our doubles facts, how can we use this to help us solve other problems.

Now we think of near doubles facts or as we call them doubles +1 or doubles -1.
For example, if know that 5+5=10, then we know that 5+6=11 because 6 is just 1 more than 5 making our answer 1 more.   Or we I know that 4+4=8, then we know that 4+3=7 because 3 is 1 less than 4 making our answer 1 less.

On Thursday, we played a game called Bugs in our Pants.  We would show an addition problem with the bugs on our blue jean work mats.   Then, we would turn that problem into a double fact.  For example, 4+2.  We put 4 bugs on one pant leg and 2 bugs on the other pant leg.  Then, we moved one of the bugs from the 4 side over to the pant leg with 2 bugs.  Now, our math problem was magically transformed into 3+3!  We can solve that in our head!!!!