Question

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

(a) 439 + 334 + 4317

(b) 1,08,737 – 47,599

(c) 8325 – 491

(d) 4,89,348 – 48,365

Answer 1

(a) 439 round *** to 400

334 round *** to 300

4317 round *** to 4300

Estimated sum = 400+300+4300 = 5000

(b) 108734 round *** to 108700

47599 round *** to 47600

Estimated difference = 108700-47600 = 61100

(c) 8325 round *** to 8300

491 round *** to 500

Estimated difference = 8300-500 = 7800

(d) 489348 round *** to = 489300

48365 round *** to = 48400

Estimated difference = 489300-48400 = 440900