2. Learning Target:
c. solve routine and non-routine problems
involving subtraction of integers using
appropriate strategies and tools.
a. perform subtraction of integers
through algebra tiles, counters, chips,
cards and number line;
b. cooperate with one’s group
mates in making an output; and
3. The grade 6 classes in a school collected 4
sacks of rice for their outreach activity.
One sack of rice was given to a needy
family. How many sacks of rice were left?
What operation should be used to solve the problem above?
MATHEMATICAL SENTENCE: +4 - +1 = N
Solution:
+4 - +1 = +3
4 units
1 units
Answer: There were 3 sacks of rice left.
+4 + -1 = +3
6. MATHEMATICAL SENTENCE: +4 - -1 = N
Let us use tiles to illustrate +4 - -1 = N
+1 +1
+1 +1
-1
+1 +1
+1 +1
+1
- = + =+1 +1
+1 +1
+1
7. In Seoul, South Korea, the temperature is -
17OC in the morning. By afternoon, the
temperature becomes -12OC. What is the
difference between the temperature in the
morning and in the afternoon?
What operation should be used to solve the problem above?
MATHEMATICAL SENTENCE: -17 - -12 = N
Solution:
Answer: The difference of the temperature in the morning and in the afternoon is -5OC
+
-17 +12
-5