Properties of Addition
7+ 0 = 7
Identity Property of Zero
345 + 234 = a
a = 579
74 - 22 = a
a = 52
345 + 234 = g
300 + 200 = g
g = 500
What is variable?
A letter that presents an unknown number in an equation.
Name the property represented below:
7 + 9 = 9 + 7
Commutative Property of Addition
6,879 + 4,565 = b
b = 11,444
876 - 288 = b
b = 588
1,987 + 2,876 = h
2,000 + 3,000 = h
h = 5,000
Susan is selling girl scout cookies. In week one she sells 18 boxes, in week two she sells 24 boxes. Her best friend sells 54 altogether. How many more boxes did her best friend sell than Susan?
18 + 24 = c
c = 52
54 - 52 = 2
She sells 2 more boxes than Susan
Name the property represented below:
(1 + 2) + 3 = 1 + (2 + 3)
Associative Property of Addition
56,123 + 76,596 = c
c = 132,719
3,865 - 1,999 = c
c = 1,866
897 - 345 = m
900 - 300 = m
m = 600
Jeff drove 345 miles to see his grandparents and another 234 miles to see his sister. How many total miles did Jeff drive?
Use estimation to check your work...
345 + 234 = m
m = 679 miles
300 + 200 = 500 miles
The estimation is close to the actual answer.
Fill in the missing piece:
8 + 5 = 5 + ____
8
785 + 12,754 = d
c = 13,539
60,000 - 24,879 = d
d = 35,121
45,876 - 23,999 = k
50,000 - 20,000 = k
k = 30,000
Robbie collected 12,868 baseball cards. His brother collected 3,860 cards. How many more cards did Robbie collect than his brother?
12,868 - 3,860 = b
b = 9,008 baseball cards
Fill in the missing piece:
(200 + 300) + 500 = ____ + (300 + 500)
200
345,986 + 987,234 = f
f = 1,333,220
872,010 - 45,898 = e
e = 826,112
67,909 - 34,989 = j
70,000 - 30,000 = j
j = 40,000
Debbie has $4,768 saved in the bank. Her sister has $2,878 saved as well. How much to the sisters have altogether?
4,768 + 2,878 = m
m = $7,646