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Worksheet
Edline

Adding and Subtracting Integers

For Students 1st - 3rd
When should you use a number line to add and subtract integers, and when should you use absolute values? Complete a set of worksheets designed to reinforce adding and subtracting integers with both standard problems and word problems....
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Lesson Plan
Curated OER

Clock Arithmetic and Cryptography

For Teachers 2nd - 5th
Learners perform basic operations in modular (clock) arithmetic. Students encode and decode messages using shift and affine ciphers. Learners apply their multiplication, division, addition, and subtraction skills.