Question

1. Find the sum by suitable rearrangement:
(a) 837 + 208 + 363
(b) 1962 + 453 + 1538 + 647
2. Find the product by suitable rearrangement:
(a) 2 x 1768 x 50
(b) 4 x 166 x 25 (c) 8 x 291 X 125
(d) 625 x 279 x 16
(e) 285 x 5 x 60 (f) 125 x 40 x 8 x 25
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Answer 1

Solution 1:

(a) 837+208+363

=(837+363)+208

=1200+208

=1408

(b) 1962+453+1538+647

= (1962+1538) + (453+647)

= 4600

Solution 2:

(a):

2\times1768\times502×1768×50

=\left(2\times50\right)\times1768(2×50)×1768

=\left(100\times1768\right)(100×1768)

=176800

Solution (b):

4\times166\times254×166×25

=\left(4\times25\right)\times166(4×25)×166

=100\times166100×166

=16600

Solution (c)

8\times125\times2918×125×291

=\left(8\times125\right)\times291(8×125)×291

=1000\times2911000×291

=291000

Solution(d):

625\times279\times16625×279×16

=\left(625\times16\right)\times279(625×16)×279

=10000\times27910000×279

=2790000

Solution (e):

285\times5\times60285×5×60

=\left(5\times60\right)\times285(5×60)×285

=300\times285300×285

=85500

Solution(f):

125\times40\times8\times25125×40×8×25

=\left(40\times25\right)\times\left(125\times8\right)(40×25)×(125×8)

=1000\times10001000×1000

=1000000