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6.NA.1 – Apply additive and simple multiplicative strategies flexibly to:
6.NA.1.a – Combine or partition whole numbers, including performing mixed operations and using addition and subtraction as inverse operations
Samples: Write numbers – to 100 000. Reading numbers – to 100 000. Comparing numbers – to 100 000.
Number and place value
ACMNA073 – Apply place value to partition, rearrange and regroup numbers to at least tens of thousands to assist calculations and solve problems
Samples: Place Value to 1000. Identifying place value to 10000 (includes empty columns). Expanded Notation Part 1.
You can go to an overview of all the curricula here.