Name _______________________________________ Date __________________ Class __________________
LESSON
2-1
Practice B
Properties and Mental Math
Simplify.
1. 17 + 4 × 5
2. 25 × 3 × 4
_______________________
4. 12 + 7 + 8 + 13
3. 28 + 39 + 11 + 22
________________________
5. 10 + 3 × 2
_______________________
7. 97 + 4 + 3 + 26
________________________
6. 9 × 8 × 5
________________________
8. 2 × 6 × 5
_______________________
________________________
9. 28 + 2 × 6
________________________
________________________
Use the Distributive Property to find each product.
10. 4 × 16
_______________
14. 5 × 29
_______________
18. 8 × 44
_______________
11. 8 × 31
12. 3 × 62
_______________
13. 2 × 46
_______________
15. 7 × 22
16. 9 × 21
_______________
________________
17. 6 × 15
_______________
19. 4 × 29
20. 7 × 31
_______________
________________
21. 5 × 57
_______________
________________
22. Each ticket to a play costs $27. How much will it cost to buy
4 tickets? Which property did you use to solve this problem
with mental math?
________________________________________________________________________________________
23. Mr. Stanley bought two cases of pencils. Each case has 20
boxes. In each box there are 10 pencils. Use mental math to find
how many pencils Mr. Stanley bought.
________________________________________________________________________________________
24. When you consider that cows eat grass and that water is needed
to grow the grass that cows eat, it takes about 65 gallons of
water to produce one serving of milk! Use mental math to find
about how many gallons of water are needed to produce 5
servings of milk.
________________________________________________________________________________________
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51
Holt McDougal Mathematics
11. 60
13. 318
15. $30
12. 152
14. 336
16. 70 students
11.
13.
15.
17.
19.
Practice B
1.
3.
5.
7.
9.
11.
13.
15.
17.
19.
21.
22.
23.
24.
37
2. 300
100
4. 40
16
6. 360
130
8. 60
40
10. 64
248
12. 186
92
14. 145
154
16. 189
90
18. 352
116
20. 217
285
$108; Distributive Property
400 pencils
325 gallons
110
60
160
258
212
1.
7
1
10
9
6
3
2
11
5
11
4
9
6
8
10
7
12
5
1
15
14
4
12
6
7
9
8
10
11
5
13
3
2
16
2
7
6
9
5
1
4
3
8
18
2.
24
1-3: Possible answers are given.
1. (a × b) × c = a × (b × c);
3.
2. a + b = b + a; a × b = b × a
a × (b + c) = (a × b) + (a × c)
150
5. 800
3,000
7. 600
255
9. 690
133
11. 2,080
310
13. 288
165
15. 259
432
17. 1,680
2,875 people
19. $475
34
4.
Review for Mastery
1.
3.
5.
7.
8.
9.
10.
120
270
210
408
592
Challenge
Practice C
3.
4.
6.
8.
10.
12.
14.
16.
18.
12.
14.
16.
18.
20.
associative
2. commutative
distributive
4. commutative
distributive
6. associative
commutative; y = 16
associative; n = 3
distributive; a = 11
distributive; b = 6
Possible answer: 15
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
A7
Holt McDougal Mathematics