This is what we did in Math on April 20, 2009
Problem of the Week:
What is the least positive integer meeting each of the following conditions?
Dividing by 7 gives a remainder of 4.
Dividing by 8 gives a remainder of 5.
Dividing by 9 gives a remainder of 6.
Integer Subtraction using chips
In pairs solve the following using (+) and (-) chips.
(+9) - (-8)= -1
0 -(+6)= -6
To subtract integers using chips (+) and(-) chips...
1. Model the first integer in the equation by using chips.
2. Then take away the number of chips indicated by the second integer.
3. "If nothing is there add a zero pair."
Note that adding zero pairs to the first integer does not change its value but does give something to take away if we need to in order to solve the question.
Here is an example:
5-7= (+)(+)(+)(+)(+) then add (+)(+)
And then we played a game where we had to go up/down the mountain/bottom of the sea then back to sea level.
And we got back our tests from Friday.
And you can also go to this website: http://www.yourteacher.com/geometry/subtractingintegers.php