Monday, 20 January 2020
Secondary Maths : Daily Short Practice
1. Use <, > or = to complete each of these statements. (1/14/2/4/T)
a. 1/3 ___ 0.3
b. 12 ½% ______ 1/8
c. 7/12 _______ 5/9
4a. Write 50 000 cm in kilometres.
A map is drawn to a scale of 1 : 50 000
b. The distance between two stations on the map is 12cm
Find the real distance between the stations in kilometres
c. The distance between two towns is 35 km. How far is this distance on the map?
5. Simplify 2x - 3(x - 2) [12/I/17/2/A]
3 5
6. The nth term of a sequence is given by 11 - 6n. Write down the first 3 terms of the sequence.
7. -2 ,1 , 4, 7
a. Write down the next 2 terms in this sequence
b. Find an expression for the nth term in this sequence. [17/I/24a/1,1/A]
<< END>>
Short Practice 9
a. When she runs 4000m, how far does she walk
Short Practice 14
S1T1 - Numbers, Power, Place Value
Integers
Whole numbers including negative whole number
Example: …,-4, -3, -2, -1, 0, 1, 2, 3, 4,…
A positive number is any number greater than zero.
Example: 1, 2, ½, 6.4
Negative Numbers
We read -1 as negative one.
A negative number is any number less than zero.
Example: -1, -2.5, -4/7
Large Numbers
One Million : 1 000 000 [6 zeros, 1000 times of thousands]
One Billion: 1000 000 000 [9 zeros, 1000 times of millions]
Index/Power
The small, raised number next to a normal letter or number, to be multiplied by itself
Example
b2= b x b
43 = 4 x 4 x 4
Square power 2 : 2
- multiplying by itself
Example
(1) Square of 4 = 42 = 4 x 4 = 16
(2) 32 = 3 x 3 = 9
(3) Square of (-5)2 = (-5) x (-5) = 25
Perfect Square are the squares of whole numbers:
(2 x 2) 4, (3 x 3) 9, (4 x 4) 16, …
Square Root - the Opposite of Square
A number that when multiplied by itself, gives the number
Symbol: √
5 --> square 52 --> 25
5 <-- Square root √25 <-- 25
Example
(1) 16 = 4 x 4
√16 = 4
(2) a2 = 25
a = + √5 x 5 = = +5
Why +5 when a number is square-root?
(-5) x (-5) = 25 ( -ve x -ve = + ve)
5 x 5 = 25
=> 25 = (-5)2 = 52 = 25
a2 = + √a x a = -a or a
Cube - Power of 3 : 3
- Multiplying the number by 3 times
Example:
(1) Cube of 3 = 33 = 3 x 3 x 3 = 27
(2) 43 = 4 x 4 x 4 = 64
(3) cube of (-5) 3 = (-5) x (-5) x (-5) = = -125
Cube Root
A value that when ‘cubed’ gives the original number
Symbol: 3√
4 --> cube 43 --> 64
4 <-- cube root 3√64 <-- 64
Example:
3√8 = 3√2 x 2 x 2 = 2
3√216 = 3√6 x 6 x 6 = 6
Prime Number
Greater than 1 that cannot be formed by multiplying 2 smaller natural number.
Example: 2, 3, 5, 7, …
2 = 1 x 2, 13 = 1 x 13
* 1 is not a prime number because prime numbers are greater than 1
* All even numbers are not prime number except 2.
Example
List all the prime number that are greater than 10 and less than 20
Step 1: List all the numbers
11, 12 , 13 , 14, 15, 16, 17, 18, 19
Step 2: Strike out the non-prime number
11, 12 , 13 , 14, 15, 16, 17, 18, 19
Step 3: List out the prime number
11, 13, 17, 19
1. Convert 125 km to m
2. Convert 299 m to km
3. Convert 700 g to kg
4. Convert 2 ton to g
5. Convert 2 hrs to seconds
6. Convert 1260 seconds to minutes
7. Convert 100 kilometres per hour into metres per second. (2/13/1/2/T)
S1T1 Number Line, Ordering , Simple Inequalities
The number line
Whole numbers, fractions and decimals can be represented on the number line.
The numbers are placed at their correct positions, equal distance apart.
Negative Numbers
We read -1 as negative one.
A negative number is any number less than zero.
Example: -1, -2.5, -4/7
Any pair of numbers eg: 3 and -3 are same distance from the origin.
Using Number Line
Example
What is the value of 3 - 5?
Ascending and Descending Orders
Ascending : Increasing in value; Moving higher/becoming bigger
[Tip to remember : A - side of A is going up, from small to big ]
Descending : Moving down in value/becoming smaller
[D => Down , from big to small]
Example
Arrange the following in ascending order
5.3, 5.25, 5.205
Step1: Arrange by the decimal point
5.3
5.25
5.205
Step2: Ascending => small to big.
Compare the number values from left to right
5.205 has the smallest hundredth value,
5.25 has the smaller tenth value
Step3: Arrange the numbers
5.205, 5.25, 5.3
Comparing and Ordering Numbers
Symbols
> greater than
< less than
≥ greater than or equal to
≤ less than or equal to
= equal
≠ not equal to
Tip to remember
4 > 3
greater = "open mouth" > “point” = less than
Similarly,
3 < 4
less than = “point” < greater = "open mouth"
Using number line and Inequalities
Using the dot : o excluding the number => < or > symbol
• including the number => ≤ or ≥ symbol
Using the symbol : > => right arrow ------>
< => left arrow <-------
Example ( > symbol)
Draw x > 2 on the number line.
Step1 : "stand" at 2, draw o (> symbol)
[To check if arrow direction is correct, use a bigger number (eg 3), and move the arrow in that direction]
Example ( < symbol )
Draw x < 1 on the number line
Steps : "stand" at 1, draw o (< symbol); then left arrow (<)
Example (≥ symbol )
Draw x ≥ 2 on the number line.
Example ( ≤ )
Draw x ≤1 on the number line.
5. Use <, > or = to complete each of these statements. (1/14/2/4/T)
a. 1/3 ___ 0.3
b. 12 ½% ______ 1/8
c. 7/12 _______ 5/9
6. Complete the number line.
<——|——|——|——|——|——|——|——|——|
-6 ___ ___ 3. 6. ___ 12 15 ____