# Question Detail

# How to create a lesson plan on mental math strategies in elementary math

Oct 23, 2017 9:28pm

- Math
- Assessment / Planning

Oct 23, 2017 9:28pm

- Math
- Assessment / Planning

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Here are some videos that might be helpful:

https://www.teachingchannel.org/videos/third-grade-mental-math

https://www.teachingchannel.org/videos/third-grade-math-routines

https://www.teachingchannel.org/videos/third-grade-math-solutions

Also, all of the videos in the series "Math Routines with Kristin Gray" are great for elementary math strategies!

In order to be flexible, efficient and accurate in mental math, students must understand some of the big ideas of mathematics. There are some that are foundational in elementary math and transcend many grade levels:

(1) composing/decomposing - break apart or combine quantities into chunks that are easier to work with. (often what's easier to work with is a foundational number, like 5, 10, 100) EX: Kindergarteners see that 7 is 2 more than 5 through visual models like rekenreks; Second graders add 26 + 38 by breaking it into 20+6+30+8 and adding the tens and ones separately. Fourth graders take 4/10 x 3 and see it as 4/10+4/10+4/10. He/she might combine 4/10+4/10+2/10 (out of the last 4/10) to make 10/10 which equals 1, then add on the last 2/10 so the sum is 1 2/10.

(2) equality/compensation - once students understand equal as "the same as" or see it as a balance between two sides, they can compute flexibily and mentally EX: A third grader might see 596 + 245 as 600 + 241 - by adding 4 to the first addend and taking 4 away from the second addend. Then, he/she can mentally add 600+241=841. No paper/pencil needed.

I recommend the book Number Talks by Sherry Parrish and/or google it and find some examples for your grade level.

Very, very powerful...