Lesson Notes By Weeks and Term - Junior Secondary School 2

SUBJECT: MATHEMATICS

CLASS:  JSS 2

DATE:

TERM: 1st TERM

 
WEEK ONE

TOPIC: BASIC OPERATION OF INTEGERS

• Definition
• Indices 
• Laws of Indices

Definition of Integer

An integer is any positive or negative whole number

Example:

Simplify the following

(+8) + (+3)    (ii) (+9) -  (+4)

Solution

(+8) + (+3) = +11        (ii) (+9) - (+4) = 9-4 = +5 or 5

Evaluation

Simplify the following

(+12) –(+7)        (ii) 7-(-3)-(-2)

Indices

The plural of index is indices

10 x 10 x 10= 103 in index form, where 3 is the index or power of 10. P5=p x pxpxpxp. 5 is the power or index of p in the expression P5.

Laws of Indices

1. Multiplication law:

ax x ay = ax+y       

E.g. a5xa3=a x a x a x a x a x a x a x a =a8

y1 x y4=y 1+4

 = y5

a3  x a5 = a3 + 5 = a8

4c4 x 3c2

= 4 x 3 x c4 x c2 =12 x c4+2=12c6

Class work 

Simplify the following

(a) 103 x 104    (b) 3 x 106 x 4 x 102    (c) p3 x p    (d) 4f3 x 5f7   

Division law

(1)  ax ÷ ay = ax ÷ ay = ax-y

Example

Simplify the following

1. a7÷a3=a x a x a x a x a x a x a ÷ a x a x a

a7-3=a4

(2) 106÷103=106÷103=106-3=103

(3) 10a7÷2a2=10a7÷2a2=5a7-2=5a5

Class work

Simplify the following

1. 105÷103  2.  51m9÷3m       (3) 8x109÷4x106   

Zero indexes

ax ÷ ax =1

By division law ax-x=a0

a0=1

E.g. 1000 =1

500=1

Negative index

a0 ÷ ax = 1/ax

But by division law, a0-x=a-x

Therefore, a-x=1/ax

Example

1. Simplify (i) b-2 (ii) 2-3

Solution

b-2 = 1/ b2        (ii) 2-3 = 1/23    = 1/2x2x2 = 1/8

Class work

(1) 10-2     (2) d0 x d4 x d-2    (3) a-3÷a-5      (4)  (1/4)-2

(5)     [am]n = amxn = amn.

[Power of index]

E.g. [a2]4= x a2 x a2 x a2 = a x a x a x a x a x a x a x a=a8

      Therefore. a2x4=a8.                                                                                                                                                                                                                      

    (6)   [mn] a=m ax na = mana. e.g. [4+2x] 2=42+22xx2 =

                    16+4x2=4[4+1xx2] =4[4+x2].                     

 7      Fractional indexes

          am/n   =a1/n xm=n√ am

Example

 (a1/2)2 =a2/2=a1=a

        (√a)2=√a x √a =√a x a=√a2=ae.g321/5=5

       √321

1.     323/5 = 5√25x3 = 23 =2x2x2 = 8
2.     272/3=3√272 = 32 =  3x3x3 = 9 
3.     4-3/2 = √1/43=        1/23
4.     (0001)3

        =1x10-3

        =(10-3)3=10-3x3=10-9

                                =        1           .

                                  1000000000

                 =0.000000001

8. (am)p/q=amp=√(a)p

e.g. (162)3/4=√ (162)3

                  = (22)3

(4)3=4x4x4 = 64

9. Equator of power for equal base

Ax=Ay That is x = y

READING ASSIGNMENT 

New General Mathematics, UBE Edition, chapter 2 Pages 24-26

Essential Mathematics by A J S Oluwasanmi, Chapter 3 pages 27-29

WEEKEND ASSIGNMENT 

1. Simplify (+13) – (+6)

    (a)7  (b) -7   (c) 19    (d) 8

2. Simplify (+11) – (+6)- (-3)

     (a)7    (b)8    (c)9     (d)10

3. Simplify 5x3 x 4x7 (a) 20x4 (b) 20x10    (c) 20x7     (d) 57x10
4. Simplify 10a8 ÷ 5a6 (a) 2a2 (b) 50a2    (c) 2a14    (d) 2a48
5. Simplify r7 ÷ r7 (a) 0 (b) 1     (c) r14    (d) 2r7

THEORY 

1.   Simplify 

1. 5y5 x 3y3
2.  24x8

        6x

2. Simplify (1/2)-3