Grade 5 · Computational Fluency
Addition and Subtraction of Whole Numbers to 1,000,000
Adding and subtracting numbers up to one million uses the same place value strategies as smaller numbers, extended one digit further. The annex-zeros strategy is powerful: 800 + 700 = 1,500 because 8 + 7 = 15, with two zeros annexed. This meta-strategy generalizes: any addition or subtraction can be simplified by identifying the core fact and applying it at the appropriate place value level.
LESSON VIDEO
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Lesson video
A short walkthrough to play in class or assign for flipped/at-home viewing.
WHAT STUDENTS WILL LEARN
✓Apply flexible computation strategies for multi-digit addition and subtraction to 1,000,000
✓Estimate sums and differences to 1,000,000 using front-end estimation and rounding
✓Solve multi-step addition and subtraction problems in real-life contexts
✓Use number talks to develop strategies for large-number computation
✓Apply mental math: annex zeros to use known facts (800 + 700 uses the fact 8 + 7 = 15)