Adding
Subtracting
Rounding
Mental Math
Vocabulary
100
What is the most important step you should complete before you begin adding or subtracting? Hint: Make sure...
Make sure the place value in each number is lined up. In a decimal, this is super simple because once the decimals are lined up, all place values automatically line up!
100
4,002 - 3,765 =
237
100
Round 4,526 to the nearest hundred.
4,500
100
Add using compatible numbers: 46 + 13 + 4
First add the 46 and 4 since they are compatible to get 50, then add the other 13 to get 63.
100
Replacing one number with another number that tells about how many or how much.
rounding
200
7,649 + 8,374 =
15,843
200
31,483 - 29,785 =
1,698
200
Round 0.472 to the nearest hundreth
0.47
200
Add using compatible numbers: 66 + 18 + 2
First add 18 and 2 because they are compatible to get 20, then add the other 66 to get 86.
200
___________________ means to add. ___________________ means to subtract.
sum & difference
300
7,110 + 499 =
7,609
300
58,005 - 1,098 =
56,907
300
Round 75.8 to the nearest whole number.
76
300
Complete the commutative property: 10 + 5 + 4 =
4 + 5 + 10
300
The numbers that are being added in an addition problem.
addends
400
5,741 + 31,018 =
36,759
400
113,300 - 1,774 =
111,526
400
Round 5,399.475 to the nearest tenth.
5,399.5
400
Complete the associative property: (10 + 3) + 2 = __ +( __ + __)
10 3 2
400
Numbers that are easy to compute mentally.
compatible numbers
500
102,369 + 60,320 =
162,689
500
454,900 - 33,870 =
421,030
500
List the three steps of rounding.
1. underline the place being asked for 2. look to the right (1-4 stick, 5-9 jump) 3. zero out the rest
500
Add using compatible numbers: 237 + 195 + 5
First add 195 and 5 to get 200, then add 237 to get 437.
500
The _____________ property states that you can add two numbers in any order. Ex. 17+9+3=3+9+17 The ____________ property says that you can change the grouping of the addends. Ex. (17+9)+3=17+(9+3)
Commutative & Associative
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