Question

Give a rough estimate (by rounding off to nearest hundreds) and also a closer estimate (by rounding off to nearest tens):

(a) 439 + 334 + 4, 317 (b) 1,08, 734 − 47, 599 (c) 8325 − 491

(d) 4, 89, 348 − 48, 365

Make four more such examples.

Answer 1

(a) 439 + 334 + 4317

Rounding off to nearest hundreds, 439, 334, and 4317 may be rounded off to 400, 300, and 4300 respectively.

Rounding off to nearest tens, 439, 334, and 4317 may be rounded off to 440, 330, and 4320 respectively.

(b) 1,08,734 − 47,599

Rounding off to hundreds, 1,08,734 and 47,599 may be rounded off to 1,08,700 and 47,600 respectively.

Rounding off to tens, 1,08,734 and 47,599 may be rounded off to 1,08,730 and 47,600 respectively.

(c) 8325 − 491

Rounding off to hundreds, 8325 and 491 may be rounded off to 8300 and 500 respectively.

Rounding off to tens, 8325 and 491 may be rounded off to 8330 and 490 respectively.

(d) 4,89,348 − 48,365

Rounding off to hundreds, 489348 and 48365 may be rounded off to 489300 and 48400 respectively.

Rounding off to tens, 489348 and 48365 may be rounded off to 489350 and 48370 respectively.