Page 96 - Maths Skills - 8

94 Maths

INTEGRATED QUESTION

G. Science Vs Maths
The rising concern among athletic trainers and health advocates regarding concussions and multiple concussions
among class - 8 football players has prompted numerous studies of the effectiveness of protective head gear
th
and the forces and accelerations experienced by players. One study suggested that there is applied force of
2 + 9x + 14 then what will be its mass and acceleration?

HOTS

Factorise the following.
1. (x + 2)(x + 25) – 10x – 20x 2. x – 11x y – 80y 8
4 4
2
2
8
3. 72y - 2 10y - 42 4. 9a b + 41a b + 20ab 3
2 2
3
Word Stock
Factor Split Divisor Expand Systematic

Activity

Objective: To verify the formula (a + b) = a + 2ab +b 2
2
2
Pre-Requisite Knowledge: Students work individually

Materials Required: Place value material (Base Ten)

Procedure: 1. The student takes a Hundreds square with
10 × 10 divisions along with Tens strips and 1 × 1 = 1 10 × 1 = 10 10 × 10 = 100
unit squares as shown in figure. Unit square Tens strip Hundreds square
2. Next, the student picks up the Hundreds square (10 × 10) and places it on a table.

3. Now, the student should place two (10 × 1) strips on teach of the two adjacent sides of this square
as shown. This gives a figure whose vertical and horizontal sides are each equal to (10 + 2) units.
But, the corner on the right is empty. So, this figure does not represent (10 + 2) .
2
4. Again, the student places four unit squares at the
corner to complete the square.

So, (10 + 2) = 10 + 2 × 10 × 2 + 2
2
2
2
= 100 + 40 + 4 = 144 unit squares
5. Consider 13 = (10 + 3) . The student should work out the square of (10 + 3) as shown below.
2
2
Thus, 13 × 13
= (10 + 3) = 10 + 2 × 3 × 10 + 3 2
2
2
= 100 + 60 + 9 = 169
Hence, (a + b) 2
= a + 2 × a × b + b = a + 2ab + b 2
2
2
2