Question

Evaluate:

(i) (0.3)³
(ii) (0.05)³
(iii) (1.5)³

Answer 1

(i) (0.3)³ = 0.3 $\times$ 0.3 $\times$ 0.3
First, we will find the product 3 $\times$ 3 $\times$ 3.
Now, 3 $\times$ 3 $\times$ 3 = 27
Sum of decimal places in the given numbers = (1 + 1 + 1) = 3
So, the product must have three places of decimal.
∴ (0.3)³ = 0.3 $\times$ 0.3 $\times$ 0.3 = 0.027

(ii) (0.05)³ = 0.05 $\times$ 0.05 $\times$ 0.05
First, we will find the product 5 $\times$ 5 $\times$ 5.
Now, 5 $\times$5 $\times$ 5 = 125
Sum of decimal places in the given numbers = (2 + 2 + 2) = 6
So, the product must have six decimal places.
∴ (0.05)³ = 0.05 $\times$ 0.05 $\times$ 0.05 = 0.000125

(iii) (1.5)³ = 1.5 $\times$1.5 $\times$1.5
First, we will find the product 15 $\times$15 $\times$ 15.
Now, 15 $\times$15 $\times$ 15 = 225 $\times$ 15 = 3375

Sum of decimal places in the given numbers = (1 + 1 + 1) = 3
So, the product must have three decimal places.
∴ (1.5)³ = 1.5 $\times$ 1.5 $\times$ 1.5 = 3.375