Properties
True or False? Name the property.
2 X 8 = 8 X 2
True
Commutative Property
5 x 6 = N
30
3 x 10 =
30
7 x N = 7
N = ?
N = 1
There were 18 seashells lying on the beach. Four of them were broken. My friend and I split the unbroken shells evenly between us. How many shells did each of us get.
Show an equation with a variable and then solve.
(18-4) ÷ 2 = N
N= 7 shells
True or False? Name the property.
(4 X 5) X 6 = (6 X 5) X 4
True
Associative Property
32 ÷ 8 =
4
14 x 10 =
140
8 x 7 = N x 8
N = 7
Mrs. Brouse had 36 Champion awards to give out. Mrs. Slitt asked for 4 more. The awards were being equally divided among 5 classrooms. How many awards were given to each classroom?
What is 8 awards?
(36 + 4) ÷ 5 = N
N = 8 awards
True or False? Explain
16 ÷ 4 = 4 ÷ 16
False
The order does matter when dividing.
18 ÷ 6 = 3
Which of the following equations is not a related fact to the number sentence above?
a. 3 x 6 = 18
b. 3 ÷ 6 = 18
c. 18 ÷ 3 = 6
d. 6 x 3 = 18
b. 3 ÷ 6 = 18
4 x 40 =
160
12 x 7 = (N + 2) x 7
N = ?
N = 10
Mrs. Bagley had 7 boxes of pencils with 10 pencils in each box. She gave out 6 pencils to students on Monday. How many pencils does Mrs. B have left?
What is 64 pencils left
(7 x 10) - 6 = N
N = 64 pencils
True or False
and why?
5 ÷ 1 = 1
False; the identity property says p X 1 = p, therefore p ÷ 1 must = p
Which ones do not belong to the fact family?
3 X 8 = 24
24 ÷ 3 = 8
8 ÷ 3 = 24
8 X 3 = 24
24 ÷ 8 = 3
24 X 3 = 8
c and f
8 x 50 =
400
3 x 4 x 5 = N x 5
N = ?
N = 12
There were 75 third graders at Bugbee School. 40 of them are girls. on Monday, 4 third grade girls and 8 third grade boys were absent. How many third grade boys were in school on Monday?
What equation could you use to solve this problem?
a. 75 ÷ 8
b. (75 - 40) - 12 =
c. (75 - 40) - 8 =
d. 75 - (40 + 4) - 8 =
100 bonus points for the solution.
c. (75 - 40) - 8 = N
N= 27 boys
True or False? Name the property and explain.
8 X 14 = (8 X 10) + (8 X 4)
True.
Distributive property states that when multiplying two factors you can break apart one factor into two addends, multiply each addend by the other factor, and then add the products together.
Solve and explain a strategy for
9 X 8 = h
h = 72
160 ÷ 10 =
16
4 x 9 = 4 x (N + 5)
N = ?
N = 4
I have $3.99. I bought 4 apples for 49 cents each. About how much money do I have left?
a. about $2.00
b. about $1.00
c. about $3.00
d. no money left
a. about $2.00 left