3.1+Subtracting+on+a+Chip+Board

27/04/09 C.T Essential Question: How do I find the difference between integers? Notes: This is the chip key which I use through out this investigation for the chip boards: **//A.Use a chip board and black and red chips to find each sum or difference.//** 1.¯8-¯7=¯1

2. 8+¯7= 1 3.¯6+¯2= ¯4

4. 6+¯2 = 4

**//How can Jing-mei show ¯8 on a ch//****//ip board so that she can remove 10 chips? What is ¯8-¯10? How did you determine your answer?//**
 * //B. Find three ways to represe//****//nt ¯8 on a chip board.//**
 * //C. Jing-mei wants to find ¯8-¯10 by using a chip board. But she gets stuck because she cannot remove 10 red chips form 8 red chips, to represent subtracting -10.//**

What Jing-mei can do is put on her chip board 10 red chips and subtract 8 chips from that. wich will give her an answer of ¯2, then she needs to convert ¯2 into a positive integer, therefore the answer will be 2.

**//→//** you are then left with 2 red chips (¯2) and convert that to positive =2 take away 8 red chips


 * //D. Drew wants to find 5-7 by using a chip board. How can he show 5 on a chip board so that he can remove 7 black chips to represent subtracting 7 ? What is 5-7? How did you determine your answer?//**

What Drew could do is take away 5 from 7 and then turn that number in to a negative number.

7-5= 2 -->convert that to a negative = ¯2 ans= 5-7=¯2

1.//** 10-12= ¯2
 * //E.Use a chip board and black and red chips to find each difference. for each difference, tell how many chips of each colour you used to represent the first integer so that you could take away chips to represent subtracting the second integer.

take away 12 ← //**2**//. 7-¯2 =5 //**3.**// ¯5-6 =1 //**4.**// ¯3-7= ¯4 **//__3.1 Follow up__//**


 * //1.Find three ways to//** **//show ¯5 on a chip board. For each representation,write a subtraction problem that would be easy to solve if you started with a representation.//**


 * [[image:Clara.T_3.1-F.U.jpg width="493" height="134"]]

2.Find each absolute value: a.** |¯7| = 7 **b.** |18|= 18 **c.**|¯42|= 42 **d.** |0|= 0


 * 3. Tell which numbers have the given number as their absolute value.

a.**12= |¯12| & |12| **b.** 3= |¯3| & |3| **c.** 31= |¯31| & |31| **d.** 100= |¯100| & |100|