\( \Large ? = 19.003 \times 22.998 - 280.010 \) \( \Large 19 \times 23 - 280 = 437 - 280 \) \( \Large = 157 = 160 \)
\( \Large ? = 5454 \div 54 \div 5 \) \( \Large \frac{5454}{54 \times 5} =\frac{5454}{270} = 20.2 = 20 \)
\( \Large 685.005 \div 5 - \sqrt{?} = 16.99 \times 6.01 \) \( \Large \sqrt{?} = \frac{685}{5} - 17 \times 6 \) \( \Large \sqrt{?} = 137 - 102 = 35 => ? = 1225 \)
\( \Large 36.0001 \div 5.9998 \times \sqrt{? = 108.0005} \) \( \Large 36 \div 6 \times \sqrt{?} = 108 \) \( \Large 6 \times \sqrt{?} = 108 \) \( \Large \sqrt{?} = 18 = 324 = 325 \)
\( \Large 1169.9997 \div 18.0011 + 7.0009 \times 4.9898 = \sqrt{?} \) \( \Large = \sqrt{?} = 1170 \div 18 + 7 \times 5 = 65 +35 = 100 \) \( \Large ? = 10000 \)
\( \Large 1178.999 \times 25.0001 - \sqrt{?} \times 16.0011 = 29075 \) \( \Large 1179 \times 25 - \sqrt{?} \times 16 = 29075 \) \( \Large 29475 - \sqrt{?} \times 16 = 29075 \) \( \Large \sqrt{?} \times 16 = 29475 - 29075 = 400 \) \( \Large \sqrt{?} = 25 => ? = 25 \times 25 = 625 \)
\( \Large \sqrt{625.04} \times 16.96 + 136.001 \div 17 = ? \)
\( \Large ? = \sqrt{625} \times 17 + 136 \div 17 \)
\( \Large 25 \times 17 + 136 \div 17 = 425 + 8 = 433 \)
\( \Large ? = \frac{3}{5} \ of \ \frac{4}{7} \ of \ \frac{7}{9} \ of \ 425 \) \( \Large ? = \frac{3}{5} \times \frac{4}{7} \times \frac{7}{9} \times 425 = 113.33 = 113 \)
\( \Large 137\% \ of \ 12345 = ? \) \( \Large ? = \frac{12345 \times 137}{100} = 16912.65 = 17000 \)
\( \Large 12.49\% \div \ of \ 839.859 = 12\% \ of \ 840 \) \( \Large \frac{840 \times 12}{100} = 100.80 = 100 \)