Add/Sub Concepts
The addition property that is shown here:
0 + 8 = 8
What is the identity property?
A letter that stands for an unknown number in an expression
42 + 38
40 + 40 = 80
5 + 6 = 11
5 and 6 are both called _______
What are addends?
Solve and CHECK
44 + 31
44 + 31 = 75
To check: 75 - 31 = 44
The addition property shown here:
9 + 6 = 15
6 + 9 = 15
What is the commutative property?
Two numbers that are added, subtracted, multiplied, or divided without an equal sign
What is an expression?
$54.92 + $23.26
$50.00 + $20.00 = $70.00
The answer to an addition number sentence
What is sum?
Solve and check your answer
56 - 16
56 - 16 = 40
To check: 40 + 16 = 56
The addition property that is shown here:
(8 + 3) + 9 = 20
8 + (3 + 9) = 20
What is the associate property?
Find the value of the variable:
h - 5 = 8
h = 13
Round to estimate and SHOW YOUR WORK
568 - 399
600 - 400 = 200
The answer to a subtraction number sentence
What is difference?
Solve and check
3051 + 1738
3051 + 1738 = 4789
To check: 4789 - 1738 = 3051
Find the sum and name the addition strategy you used:
7 + 8
7 + 8 = 15
We used doubles to find the answer.
8 + 8 = 16
so 7 + 8 = 15
Find the value of the variable
9 - c = 0
c = 9
Round to estimate and SHOW YOUR WORK
4327 + 631
4300 + 600 = 4900
12 - 5 = 7
5 is called the _______
What is subtrahend?
Solve and check
6759 - 542
6759 - 542 = 6217
To check: 6217 + 542 = 6759
Show how you would use the "sums of 10" strategy to find the answer to 9 + 6
10 + 6 = 16
So 9 + 6 = 15
Write a problem to match the expression:
13 - x
Example: Ms. Dieckman had 13 pencils. She gave some away. What expression shows how many pencils she has left?
Round to estimate and SHOW YOUR WORK
65,571 - 4,497
66,000 - 4,000 = 62,000
12 - 5 = 7
12 is called the ________
What is the minuend?
Solve and check
$23.74 + $1.12 + $0.13
$23.74 + $1.12 + $0.13 = $24.99
To check: Add in reverse order!
$0.13 + $1.12 + $23.74 = $24.99