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October 23
Flex Math Update
by  elizabeth.howlettNo presence information  on 10/23/2018 7:44 PM

​In my flex math group this week we are focusing on the reciprocal relationship between addition/subtraction.

For example: If I know that 25 + 75 = 100 I also know...

  • 75 + 25 = 100
  • 100 - 25 = 75
  • 100 - 75 = 25

We will be using this knowledge to find the missing term in an equation, especially when dealing with subtractions. Because addition tends to come more naturally, we can simplify the process by thinking of a reciprocal addition for a subtraction. 

For example:  If I'm trying to solve 357 - 178 = x I can also think...

  • 178 + x = 357
To find the answer to the equation, we will be using a Number Line. Students simply place the first term they know (178) at the beginning of the number line and the sum they want to get to (357) at the end. Then, they can add in comfortable chunks until they get to the target number.

number line.png


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