March 11th - Investigation 2.2 and 2.3

Today we continued to look at integers and specifically subtracting integers.

We worked with the following number sets:

-8 - -3 =

8 -3 =

8 - -3 =

-8 - 3 =

-3 - -8 =

The following were the rules/ algorithms we came up with.

1. You will get a positive number if the number you start with is greater than the number you subtract it from.

2. If the first number is less than the second number then the difference will be negative.

Another student then said:
3. If the first number is greater than the second then the difference will be positive.

We had good discussions and a good use of the chip model today.

Here is an interactive link to chip models. 
Open in Safari

Math this Week - 27th, 28th, and 1st of March

We worked through Investigation 1.  Students were aquatinted with number lines, read thermometers and how to use the chip model to work with adding and subtracting positive and negative integers.

Here is a cool interactive link working with the chip model.
Click here to access.  You will need to open this in Safari!

Here is a good link to Math is Fun on Number Lines.