All 100 targets have a solution.
\(1 = ( 499 \cdot 0 )!\)
\(2 = \sqrt{94 - 90 }\)
\(3 = 4 - 99^{0 }\)
\(4 = 94 - 90 \)
\(5 = 99^{0} + 4 \)
\(6 = \frac{ 90 }{ 9 } - 4 \)
\(7 = 0 \cdot 9 + \sqrt{49 }\)
\(8 = 9 - 49^{0 }\)
\(9 = 49 \cdot 0 + 9 \)
\(10 = 49^{0} + 9 \)
\(11 = \sqrt{9 \cdot 9 + 40 }\)
\(12 = \frac{ 90 }{ 9 } + \sqrt{4 }\)
\(13 = 40 - \sqrt{9} \cdot 9 \)
\(14 = \frac{ 90 }{ 9 } + 4 \)
\(15 = \frac{ 90 }{ \sqrt{4 \cdot 9 } }\)
\(16 = \sqrt{40 + 9} + 9 \)
\(17 = 9 - 4^{0} + 9 \)
\(18 = \frac{ 90 }{ 9 - 4 }\)
\(19 = 4^{0} + 9 + 9 \)
\(20 = \sqrt{409 - 9 }\)
\(21 = \sqrt{( 40 + 9 ) \cdot 9 }\)
\(22 = 40 - 9 - 9 \)
\(23 = 4! - 99^{0 }\)
\(24 = ( 94 - 90 )!\)
\(25 = 99^{0} + 4 !\)
\(26 = \frac{ 90 }{ \sqrt{9} } - 4 \)
\(27 = ( 4 - 9^{0} ) \cdot 9 \)
\(28 = 40 - 9 - \sqrt{9 }\)
\(29 = ( 0! + 9 ) \cdot \sqrt{4} + 9 \)
\(30 = ( 9 - 4 )! - 90 \)
\(31 = 40 - \sqrt{9 \cdot 9 }\)
\(32 = ( 9 - 9^{0} ) \cdot 4 \)
\(33 = \frac{ 99 }{ 4 - 0 ! }\)
\(34 = 40 - 9 + \sqrt{9 }\)
\(35 = 4 \cdot 9 - 9^{0 }\)
\(36 = \frac{ 90 }{ \sqrt{4} } - 9 \)
\(37 = 40 - \frac{ 9 }{ \sqrt{9 } }\)
\(38 = \frac{ 90 + 4! }{ \sqrt{9 } }\)
\(39 = 40 - \frac{ 9 }{ 9 }\)
\(40 = 40 - 9 + 9 \)
\(41 = 90 - 49 \)
\(42 = \frac{ 90 }{ \sqrt{4} } - \sqrt{9 }\)
\(43 = \frac{ 9 }{ \sqrt{9} } + 40 \)
\(44 = 4 \cdot 9 - 0! + 9 \)
\(45 = ( 9 - ( 0 + 4 ) ) \cdot 9 \)
\(46 = 40 - \sqrt{9} + 9 \)
\(47 = 49 + 0! - \sqrt{9 }\)
\(48 = 49 - 9^{0 }\)
\(49 = 0 \cdot 9 + 49 \)
\(50 = 9^{0} + 49 \)
\(51 = 49 - 0! + \sqrt{9 }\)
\(52 = 40 + \sqrt{9} + 9 \)
\(53 = 49 + 0! + \sqrt{9 }\)
\(54 = 90 - 4 \cdot 9 \)
\(55 = 40 + \sqrt{9}! + 9 \)
\(56 = \frac{ \sqrt{49}! }{ 90 }\)
\(57 = 49 - 0! + 9 \)
\(58 = 40 + 9 + 9 \)
\(59 = 99 - 40 \)
\(60 = \frac{ 40 \cdot 9 }{ \sqrt{9 }! }\)
\(61 = ( 0 + 4 )^{\sqrt{9}} - \sqrt{9 }\)
\(62 = \sqrt{49} \cdot 9 - 0 !\)
\(63 = \sqrt{40 + 9} \cdot 9 \)
\(64 = \sqrt{49} \cdot 9 + 0 !\)
\(65 = 9^{0} + 4^{\sqrt{9 }}\)
\(66 = 90 - 4 \cdot \sqrt{9 }!\)
\(67 = \sqrt{9} \cdot 9 + 40 \)
\(68 = ( 9 - 0! + 9 ) \cdot 4 \)
\(69 = 90 - 4! + \sqrt{9 }\)
\(70 = ( 0! + 9 ) \cdot \sqrt{49 }\)
\(71 = ( 9 + 9 ) \cdot 4 - 0 !\)
\(72 = 90 - \sqrt{4} \cdot 9 \)
\(73 = ( 0 + 4 )^{\sqrt{9}} + 9 \)
\(74 = 99 - 0! - 4 !\)
\(75 = 90 - 4! + 9 \)
\(76 = 99 + 0! - 4 !\)
\(77 = 90 - 4 - 9 \)
\(78 = 90 - 4 \cdot \sqrt{9 }\)
\(79 = 90 - \sqrt{4} - 9 \)
\(80 = 9 \cdot 9 - 4^{0 }\)
\(81 = ( 0 \cdot 4 + 9 ) \cdot 9 \)
\(82 = 4^{0} + 9 \cdot 9 \)
\(83 = 90 - \sqrt{49 }\)
\(84 = 90 - \sqrt{4 \cdot 9 }\)
\(85 = 90 + 4 - 9 \)
\(86 = 94 + 0! - 9 \)
\(87 = \sqrt{90^{\sqrt{4}}} - \sqrt{9 }\)
\(88 = 90 + 4 - \sqrt{9 }!\)
\(89 = 90 - 4 + \sqrt{9 }\)
\(90 = ( 4 - \sqrt{9} ) \cdot 90 \)
\(91 = 90 + 4 - \sqrt{9 }\)
\(92 = 90 - 4 + \sqrt{9 }!\)
\(93 = 94 - 9^{0 }\)
\(94 = 0 \cdot 9 + 94 \)
\(95 = 90 - 4 + 9 \)
\(96 = \sqrt{4 \cdot 9} + 90 \)
\(97 = \sqrt{9409 }\)
\(98 = 99 - 4^{0 }\)
\(99 = 0 \cdot 4 + 99 \)
\(100 = 4^{0} + 99 \)