7th Grade Math: Week of 102609

1
7th Grade Math Week of 10/26/09

• Noreen Habana
• North Huron Schools

2
Review

• Use integer chips to model addition and
  subtraction of integers.
• Whiteboard Practice draw integer chips and
  rewrite subtraction expressions into addition
  expressions before solving.
• P.75 9-16
• Rewrite each subtraction expression into
  addition expression

3
HW2.4 19-28

• On a separate sheet of paper, do p.75 19-28.
• Use a 2 column format.
• For work, copy each problem, then rewrite them
  into addition expressions and solve.

4
Warm Up

• 1.   (3 8 5) 5
• 2.   4 - (3 92 3)
• 3.   (42 4 - 5)
• 4.   6 - (1 8) 12 1
• 5.   (82 5) - 1 - 1

5
Additional Practice Integers

• http//www.mathwarehouse.com/arithmetic/operations
  /subtraction/student-worksheets/add-subtract-integ
  ers-worksheet.pdf

6
Adding and Subtracting Integers

• Simplifying the rules.
• Change subtraction problems into addition
  problems.
• Same signs add the numbers, keep the sign
• Different signs subtract the numbers, the sign
  you have more of, stays

7
Sect. 2.5 Multiplying and Dividing Integers

• Multiplication is addition of repeated set.
• Ex. 3 3 3 3 4 groups of a set of 3
• or 4 x 3 12.

8
Sect. 2.5 Multiplying and Dividing Integers

• Express 3 -3 -3 -3 as a multiplication
  expression.
• Show 4(-3) using integer chips.
• 4(-3) -12

9
Sect. 2.5 Multiplying and Dividing Integers

• Show -4(3) using integer chips.
• Since 4(3) 12, -4(3) -12
• Read the negative in front as opposite of.

10
Sect. 2.5 Multiplying and Dividing Integers

• Show -4(-3) using integer chips.
• Since 4(-3) -12, -4(-3) 12
• Read the negative in front as opposite of.

11
Multiplying integers

• The negative in front of a multiplication
  expression undoes or does the opposite of the
  set.
• Positive x positive positive
• Positive x negative negative
• Negative x positive opposite of positive
  negative
• Negative x negative opposite of negative
  positive

12
Multiplying Integers

• Draw integer chips for the following problems,
  then solve.
• A) 5 x 3
• B) 4 x 2
• C) 2 x 5
• D) 3 x -2

13
Dividing Integers

• Division is the inverse or opposite operation of
  multiplication.
• The rules for multiplying integers apply to
  dividing integers
• Positive positive positive
• Positive negative negative
• Negative positive opp. of positive negative
• Negative negative opp. of negative positive

14
Multiplying and Dividing Integers

• Simplify the rules
• Same signs positive
• Different signs negative

15
Additional Practice multiply and divide integers