Approximations Part 1

1)49.6*5.08 + 485.987 +42.6+5.3 = ?

  1. 740      2.780       3.720    4.760   5.800

50 * 5  +  486  +  \frac{40}{5}

250  +  486  +  8 = 746 it is near to 740

2)(64.15)^{2}-(17.90)^{2}-(21.9)^{2}=?

1.3600  2.3900  3.3300  4.4000   5.3000

64^{2}-18^{2}-22^{2}

4096 – 324  – 484 = 3288 it is near to 3300

3)(\sqrt{900.021}-\sqrt{255.989})^{2}\div (\sqrt{575.989}-\sqrt{289.006})^{2}=?

(\sqrt{900}-\sqrt{256})^{2}\div (\sqrt{576}-\sqrt{289})^{2}

(30-16)^{2}\div (24-17)^{2}

\frac{14\times 14}{7\times 7}=4

4)9.09% of 1334 + 14.30% of 2400 =?

1.486  2.465  3.450  4.430  5.418

9.09% of 1334 +14.28% of 2400

\frac{1}{11}\times 1334+\frac{1}{7}\times 2400

121+343 = 464 it is near to 465

5)33\frac{1}{3}% of 768.9 + 25% of 161.2 – 58.12 = ?

1.250  2.220  3.230  4.200  5.240

\frac{1}{3}\times 768+\frac{1}{4}\times 160-58

256 + 40 -58 =238 which is near to 240