Friday, November 18, 2016

Subtraction Strategies

Lesson Introduction:
As a whole class, students counted by 2s, 5s and 10s. First, they counted forwards from a given number. Next, they counted backwards from a given number.

Questions:
Why is it important to know skip counting facts? How can the backward skip-counting strategy help us with subtraction questions?

Students were split into 3 groups. Each group was given success criteria for their given strategy. At the end of the lesson and activity, students shared the strategy they used with the rest of the class.

Group 1
We are learning to:
Use the near-doubles subtraction strategy

I know I am successful if I can:
-Use near-doubles to subtract one number from another
-Use doubles mental math skills before writing the number sentence
-Describe the near-doubles strategy I have used

Group 2:
We are learning to:
Use the split subtraction strategy

I know I am successful if I can:
-Use the split strategy to separate the 2nd number in the subtraction number sentence
-Subtract the remaining numbers in the number sentence
-Describe the split strategy I have used

Group 3:
We are learning to:
Use the jump subtraction strategy

I know I am successful if I can:
-Use the number line to jump in tens and in units (ones)
-Count back in tens and ones on a number line to help me subtract
-Describe the jump strategy I have used

No comments:

Post a Comment