North Penn School District
Elementary Math Parent Letter
Grade 1
Unit 2-A -- Chapter 3: Subtraction Concepts
Examples from each lesson
Lesson 3.1
More information on this strategy is available on Animated Math Model #12.
Lesson 3.2
More information on this strategy is available on Animated Math Model #13.
Lesson 3.3
More information on this strategy is available on Animated Math Model #14.
Lesson 3.4
More information on this strategy is available on Animated Math Models #15, 16.
Lesson 3.5
More information on this strategy is available on Animated Math Model #16.
Lesson 3.6
More information on this strategy is available on Animated Math Models #13, 14,
15, and 16.
Lesson 3.7
Lesson 3.8
More information on this strategy is available on Animated Math Model #17.
Lesson 3.9
More information on this strategy is available on Animated Math Model #17.
Lesson 3.10
More information on this strategy is available on Animated Math Model #18.
Lesson 3.11
More information on this strategy is available on Animated Math Model #18.
Lesson 3.12
Vocabulary
Count on – to count forward from a given number
Doubles – an addition fact that includes two of the same number, such as 5 + 5
Doubles plus one – an addition fact with a double to add and then add one, such as 5 + 6
Doubles minus one – an addition fact with a double to add and then subtract one, such as 5 + 4
Make a ten – a strategy that teaches children to isolate a ten first to help them add numbers
whose sum is greater than ten