Evaluate: 10.1 × 10.2

Solution:

Given,10.1 × 10.2 = (10 + 0.1) (10 + 0.2)

Using standard identity: (x + a) (x + b) = x² + (a + b)x + ab

Here, x = 10, a = 0.1 and b = 0.2

10.1 × 10.2 = (10 + 0.1) (10 + 0.2)

= 10² + (0.1 + 0.2)10 + (0.1)(0.2)

= 100 + 3 +0.02 = 103.02

✦ Try This: Evaluate: 10.6 × 10.9

Given,10.6 × 10.9 = (10 + 0.6) (10 +0.9)

Using standard identity: (x + a) (x + b) = x² + (a + b)x + ab

10.6 × 10.9 = (10 + 0.6) (10 +0.9)

= 10² + (0.6 + 0.9)10 + (0.6)(0.9)

= 100 + 15 + 0.54 = 115.54

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 9

NCERT Exemplar Class 8 Maths Chapter 7 Problem 86(xv)

Evaluate: 10.1 × 10.2

Summary:

Evaluating 10.1 × 10.2 we get, 103.02

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