Math 1 · Lesson 1 · Identity and inverse · part 1 of 6
Warm-up: change nothing, undo everything
Answer these four on paper before reading on.
Warm-up: change nothing, undo everything
Answer these four on paper before reading on.
Change nothing
(a) What can I add to 7 so it is still 7?
(b) What can I multiply 7 by so it is still 7?
Undo everything
(c) What do I add to 7 to get 0?
(d) What do I multiply 7 by to get 1?
Check your four answers
0, 1, -7, and 17. If you wrote -7 for (d), you are not alone. That mix-up is exactly what this lesson fixes.
Two of those numbers did nothing. Two of them undid everything. Today is about those four numbers.