Question 1

125.009 + 69.999 + 104.989 =?

Accepted Answer

125.009 + 69.999 + 104.989 = ? Lets assume, each value is approximated to nearest whole number ⇒ ? ≈ 125 + 70 + 105 ⇒ ? ≈ 300

Question 2

16.003 x 27.998 - 209.010 =?

Accepted Answer

? = 16.003 x 27.998 - 209.010 ? ≈ 16 x 28 - 210 = 448 - 210 ? = 238 ≈ 240

Question 3

840.003 ÷ 23.999 =?

Accepted Answer

? = 840.003 ÷ 23.999 Here one number is increased and other is decreased to their nearest whole number = 840 ÷ 24 = 35

Question 4

6885.009 - 419.999 - 94.989 =?

Accepted Answer

? = 6885.009 - 419.999 - 94.989 = 6885 - 420 - 95 ≈ 6370

Question 5

503 x 201=?

Accepted Answer

530 x 201 = 101103 ≈ 101100

Question 6

(2/3) x (6/8) x (2/3) x (3/4) =?

Accepted Answer

(2/3) x (6/8) x (2/3) x (3/4) = 1/4 = 0.25

Question 7

15 7/ 8 x 23 1/ 5 + 3 4/ 5 x 5 1/ 8 =?

Accepted Answer

? = 127/8 x 116/5 + 19/5 x 41/8 = 14732/40 + 779/40 = 15511/40 = 387.7 ≈ 385

Question 8

2 3/ 5 x 15/26 x 283.75 =?

Accepted Answer

? = 23/5 x 15/26 x 283.75 ≈ 13/5 x 15/16 x 284 = 426 ≈ 425

Question 9

36.98276421 x 21.00002 =?

Accepted Answer

36.98276421 x 21.00002 Using nearest value in whole number for 36.9827421 is 37 and 21.0002 is 21 ≈ 37 x 21 = 777 ≈ 775

Question 10

14.995 x 8.001 x 20.991 =?

Accepted Answer

? = 14.995 x 8.001 x 20.991 ≈ 15 x 8 x 21 = 2520

Question 11

26.823 x 27.923 x 4.5001 =?

Accepted Answer

26.823 x 27.923 x 4.5001 ≈ 27 x 28 x 4.5000 = 756 x 4.5000 = 3402 ≈ 3400

Question 12

3739 + 164 x 27 =?

Accepted Answer

3739 + 164 x 27 = ? ? = 3739 + 4428 = 8167 ≈ 8200

Question 13

21 + 3.7 x 2.9 =?

Accepted Answer

21 + 3.7 x 2.9 = ? ? ≈ 21+ 4 x 3 ≈ 21 + 12 ≈ 33 ≈ 32

Question 14

(21 + 99) x (30 - 19.02) =?

Accepted Answer

(21+ 99) x (30 - 19.02) ≈ (21+ 99 ) x (30 - 19) ≈ 120 x 11 = 1320

Question 15

198.001 x 25 + 112.05 x 24.998 =?

Accepted Answer

? = 198.001 x 25 + 112.05 x 24.998 = 198 x 25 + 112 x 25 = 25(198 + 112) = 25 x 310 = 7750

Question 16

17.995 x 16.005 +15.999 x 15.001 =?

Accepted Answer

? = 17.995 x 16.005 + 15.999 x 15.001 = 18 x 16 + 16 x 15 = 16 x ( 18 + 15) = 16 x 33 = 528

Question 17

127.007 x 7.998 + 6.05 x 4.001 =?

Accepted Answer

? = 127.007 x 7.998 + 6.05 x 4.001 = 127 x 8 + 6 x 4 = 1016 + 24 = 1040

Question 18

198.995 x 12.005 + 16.25 x 6.95 =?

Accepted Answer

? = 198.995 x 12.005 + 16.24 x 6.95 = 199 x 12 +16 x 7 = 2388 + 112 = 2500

Question 19

2375.85 ÷ 18.01 - 4.525 x 8.05?

Accepted Answer

? = 2375.85 ÷ 18.01 - 4.525 x 8.05 = 2376 ÷ 18 - 4.5 x 8 = 132 - 36 = 96

Question 20

2508 ÷ 15.02 +? x 11 = 200

Accepted Answer

2508 ÷ 15.02 ÷ ? x 11 = 200 ⇒ 2508/15 + ? x 11 = 200 ∴ ? = (200 - 167.2) x 1/11 = 2.98 ≈ 3

Approximation Questions