Estimate the value of 87 x 71.

__solution__
round off to tens;

87 ≈ 90 [approximating to 90]

71 ≈ 70 [approximating to 70]

= 90 x 70

= 6300

__Hence 87 x 71__

__≈__

__6300__

__TRY THIS...................__
Estimate the value of 61 x 69.[

*]***ans. 4200**