Vocabulary
What is the identity property
4+0= 4
a number plus zero equals the number
56+34
90
42-12=
30
round to the nearest hundred
348
x+2= 7
x=5
what is the associative property?
the grouping of addends does not change the answer
(3+2)+1= 3+(2+1)
567+ 724
1,291
174-53=
121
round to the nearest 10 and solve
46+ 36
50+40=90
14-3 + b= 16
b=5
Which property states that numbers can be added in any order and still have the same answer?
Commutative
6,425+ 3,422
9,847
546-249
297
round to the nearest hundred and solve
4768 - 2345
4,800-2,300=2,500
Jack had $30 he went to the movies and spent $5 on his ticket, he also spent $15 on snacks. After the movie he found $2 on the floor outside the theater. How much money did he have at the end?
Write the equation using a variable
30-5-15+2=m
m=12
45-0=45
45-45=0
These two problems are examples of
subtraction rules
307,687+ 456,987
764,674
4,707- 2,528
2179
round to the nearest hundred
7654+ 345=
7,700+ 300=8,000
June takes Some money to a school trip. She spends $17 on lunch and $28 on souvenirs. She still has $16. How much money did she take on the trip?
Write and solve for a variable.
s -17-28=16
16+17+28
s=61
What are the minuend and subtrahend?
the minuend is a number from which another number is subtracted.
a subtrahend is the number being subtracted
456 + _______= 756
300
50,000-24,324
25,676
What is rounding?
to change a number so it is easier to do math with
what is a variable?
A variable is a letter or symbol that represents an unknown value