MA19.1.14
Given a two-digit number, mentally find 10 more or 10 less than the number without having to count, and explain the reasoning used.
Given a two-digit number, mentally find 10 more or 10 less than the number without having to count, and explain the reasoning used.
Unpacked Content
UP:MA19.1.14
Vocabulary
- Ten more
- Ten less
Knowledge
- how to mentally find 10 more or 10 less of a two digit number and explain reasoning.
- place value vocabulary: tens, ones.
Skills
- mentally add or subtract 10 from a number in the range from 1
- 100.
- Explain their reasoning using place value understanding and patterns.
Understanding
- patterns in the place value system can be used to mentally compute sums and differences.