Pre Algebra - Lesson 4: Multiplying and Dividing Negative Numbers

Exercises


Question 1
Work out the answers to the following multiplications without using a calculator:

(a) (-7) × 2 = __
(b) (-4) × 8 = __
(c) (-2) × (-5) = __
(d) (-6) × (-3) = __
(e) (-3) × 7 = __
(f) (-10) × (-4) = __
(g) 8 × 4 = __
(h) 3 × (-6) = __
(i) (-7) × (-2) = __
(j) (-4) × (-5) = __
(k) (-7) × 0 = __
(l) 8 × (-5) = __

Question 2
Work out the answers to the following divisions without using a calculator:

(a) (-10) ÷ (-2) = __
(b) (-15) ÷ 5 = __
(c) 18 ÷ (-3) = __
(d) 14 ÷ (-7) = __
(e) (-21) ÷ (-3) = __
(f) (-45) ÷ 9 = __
(g) 50 ÷ (-5) = __
(h) (-100) ÷ (-4) = __
(i) 80 ÷ (-2) = __
(j) 26 ÷ (-13) = __
(k) (-70) ÷ (-7) = __
(l) (-42) ÷ 7 = __

Question 3
Complete these multiplication tables:

(a)

× __ -1 __ 2 __ __ __ __ -2 2 __ -3 __ __ -9

(b)

× -2 __ __ __ 10 __ __ -2 __ 6 __ 3 __ __ -12

Question 4
Fill in the missing numbers in these calculations:

(a) __ × 5 = -20
(b) (-80) ÷ __ = 4
(c) 16 × __ = -32
(d) (-4) × __ = 32
(e) __ × (-3) = 12
(f) 40 ÷ __ = -8
(g) -8 × __ = 48
(h) -32 ÷ __ = 4
(i) 15 × __ = -60
(j) 100 ÷ __ = -25

Pre Algebra - Lesson 3: Adding and Subtracting Negative Numbers

Exercises:

Question 1
Use a number line to work out the following calculations:

(a) -4 + 6 =__
(b) -5 + 8 =__
(c) -1 + 3 =__
(d) -4 + 7 =__
(e) 2 + (-3) =__
(f) -1 + (-4) =__
(g) -2 + (-3) =__
(h) -6 + 6 =__
(i) -7 + 4 =__
(j) -6 + 2 =__
(k) -7 + 2 =__
(l) 5 + (-5) =__

Question 2
Use a number line to calculate:

(a) 4 - 6 =__
(b) 5 - 7 =__
(c) 2 - 4 =__
(d) -1 - 1 =__
(e) -3 - 2 =__
(f) -4 - (-1) =__
(g) 3 - (-4) =__
(h) 5 - (-6) =__
(i) 8 - 12 =__
(j) -5 - (-1) =__
(k) 4 - 9 =__
(l) -4 - (-4) =__

Question 3
Fill in the missing number in each of these equations:

(a) 4 +__ = 1
(b) 3 -__ = -6
(c) -6 +__ = -7
(d) __+ 7 = 2
(e) __- 7 = -8
(f) 4 -__ = 7

Question 4
Make number lines for each section (S._).

(S.a) 10, 8, 6, 4,
(S.b) -10, -7, -4, -1,
(S.c) 19, 14, 9, 4,
(S.d) -1, -3, -5, -7,
(S.e) -20, -16, -12, -8,
(S.f) -5, -10, -15, -20,
(S.g) 18, 15, 12, 9,
(S.h) -16, -12, -8, -4,

Question 5
Overnight, the temperature dropped from 5 ºC to -14 ºC.
By how many degrees did the temperature fall?

C: 5º__-14º=__
A:The temperature fell __ degrees.

Question 6
One day the level of the water in a river was 30 cm above its average level.
One week later it was 12 cm below its average level.
How far did the water level drop in the week?

C:30cm__12cm=__
A:The water level dropped __cm in the week.


Question 7
A chest of treasure was hidden in the year 64 BC and found in 284 AD.
For how long was the chest hidden?

C:64__284=__
A:The chest was hidden for __ years.

Pre Algebra - Lesson 2: Order of Operations II

Exercises:

1. 1 − (1 × 4 × 5 ÷ 2)=
2. (16 ÷ 4 × 3)=
3. 8 + 6 × (8 ÷ 4) + 4=
4. (6 − 7) − 7=
5. 2 + 3 × (15 ÷ 3 + 7)=
6. (4 − 4) + 2=
7. (3 + 8) + 6 + 9=
8. 2 − (5 − 9) × 4=
9. (1 + 8) + 8=
10. (7 × 5 − 2) + 5 − 2=
11. 2 × (1 − 1 + 4)=
12. (7 + 8) + 3=
13. (9 + 9 × 5) − 7 − 5=
14. (3 + 4) + 3=
15. 4 − (1 − 3) × 6=
16. (9 − 4 + 9)=
17. (1 × 2 × 5)=
18. 1 + 9 + (9 ÷ 3 + 2)=
19. 3 - (5 - 2 + 7)=
20. (2 − 5 − 9)=
21. (4 × 9 − 3) + 9 - 7=
22. (6 ÷ 3) × 6=
23. (6 ÷ 2 − 3)=
24. (8 × 3 + 2) × 9=
25. 5 + (6 − 6 + 3)=
26. 9 × (5 − 3) ÷ 6=
27. (8 × 3) − 8=
28. (9 − 1) − 5=
29. 7 × 6 − (1 + 4 − 2)=
30. (5 × 4 + 5) + 7 ÷ 8=

Pre Algebra - Lesson 1: Order of operations

This is the first video lesson of Pre-Algebra by Khan Academy




Exercises for this lesson:

1 - 5 x 6 =

2 - 5 - 9 =

4 ÷ 2 - 3 =

4 - 9 + 4 =

3 + 10 x 9 =

9 - 5 - 2 =

8 + 1 x 9 =

10 - 5 + 9 =

5 + 9 + 9 =

6 + 3 ÷ 1 =

5 ÷ 5 x 1 =

1 - 2 + 4 =

6 x 7 x 10 =

7 x 10 + 4 =

8 x 8 x 9 =