Negative numbers appear for the first time in history in the Nine Chapters on the Mathematical Art, which dates from the period of the Han Dynasty (202 BC – 220 AD), but may well contain much older material. The mathematician Liu Hui (c. 3rd century AD) established rules for the addition and subtraction of negative numbers.
DIRECTED NUMBER
Do two negatives make a positive?
Key questions
1. What are directed numbers?
2. Can we order any list of numbers?
3. How do we add or subtract directed numbers?
4. How do we multiply or divide directed numbers?
~2 lessons
Literacy
stories that set a frame or background
stories that accompany or intertwine
stories that introduce
stories that explain
stories that ask a question
stories that entertain
Numbed! by David Lubar
Introducing...
directed numbers intro - 1, 3
four points - 1, 3
ordering fluency - 2
smile directed numbers - 1, 2, 3, 4
temperature change - 1, 3
tug of war - 1, 3