1. 直接写出得数。
$650 - 543 = $ $200×6 = $ $33×2 = $ $302×6≈$
$911 - 511 = $ $600×7 = $ $72×5 = $ $596×2≈$
$135 + 415 = $ $30×4 = $ $51×3 = $ $148×3≈$
$925 - 95 = $ $400×9 = $ $62×4 = $ $698×5≈$
$28 + 172 = $ $80×2 = $ $28×3 = $ $247×4≈$
$480 + 460 = $ $60×5 = $ $32×3 = $ $159×5≈$
$700 - 290 = $ $110×3 = $ $41×5 = $ $229×4≈$
$\frac{1}{6} + \frac{4}{6} = $ $\frac{5}{8} - \frac{3}{8} = $ $1 - \frac{3}{5} = $ $\frac{3}{7} + \frac{2}{7} = $
$\frac{4}{10} + \frac{5}{10} = $ $\frac{5}{9} - \frac{3}{9} = $ $\frac{1}{4} + \frac{2}{4} = $ $\frac{10}{11} - \frac{7}{11} = $
$\frac{3}{12} + \frac{9}{12} = $ $\frac{3}{4} - \frac{1}{4} = $ $1 - \frac{1}{2} = $ $\frac{1}{5} + \frac{2}{5} = $
$1 - \frac{6}{7} = $ $\frac{2}{3} + \frac{1}{3} = $ $\frac{7}{10} - \frac{3}{10} = $ $\frac{5}{6} - \frac{2}{6} = $

$650 - 543 =107$，$200×6 =1200$，$33×2 =66$，$302×6≈1800$
$911 - 511 =400$，$600×7 =4200$，$72×5 =360$，$596×2≈1200$
$135 + 415 =550$，$30×4 =120$，$51×3 =153$，$148×3≈450$
$925 - 95 =830$，$400×9 =3600$，$62×4 =248$，$698×5≈3500$
$28 + 172 =200$，$80×2 =160$，$28×3 =84$，$247×4≈1000$
$480 + 460 =940$，$60×5 =300$，$32×3 =96$，$159×5≈800$
$700 - 290 =410$，$110×3 =330$，$41×5 =205$，$229×4≈920$
$\frac{1}{6} + \frac{4}{6} =\frac{5}{6}$，$\frac{5}{8} - \frac{3}{8} =\frac{2}{8}=\frac{1}{4}$，$1 - \frac{3}{5} =\frac{2}{5}$，$\frac{3}{7} + \frac{2}{7} =\frac{5}{7}$
$\frac{4}{10} + \frac{5}{10} =\frac{9}{10}$，$\frac{5}{9} - \frac{3}{9} =\frac{2}{9}$，$\frac{1}{4} + \frac{2}{4} =\frac{3}{4}$，$\frac{10}{11} - \frac{7}{11} =\frac{3}{11}$
$\frac{3}{12} + \frac{9}{12} =\frac{12}{12}=1$，$\frac{3}{4} - \frac{1}{4} =\frac{2}{4}=\frac{1}{2}$，$1 - \frac{1}{2} =\frac{1}{2}$，$\frac{1}{5} + \frac{2}{5} =\frac{3}{5}$
$1 - \frac{6}{7} =\frac{1}{7}$，$\frac{2}{3} + \frac{1}{3} =1$，$\frac{7}{10} - \frac{3}{10} =\frac{4}{10}=\frac{2}{5}$，$\frac{5}{6} - \frac{2}{6} =\frac{3}{6}=\frac{1}{2}$

2. 在$○$里填上“$＞$”“$＜$”或“$=$”。
$3×4÷4◯$$3×1$ $(48 - 36)÷3◯$$3×9×0$
$70×8◯$$71×8$ $178 - 84 - 33◯$$178 - (84 + 33)$
$8×3◯$$5×8 - 30$ $27÷3 + 18◯$$27 + 3×18$
$8÷4÷2◯$$8÷(4×2)$ $430 - 184 + 75◯$$430 - 184 - 75$
$12×2×5◯$$12×5×2$ $28 + 3×30◯$$28×3 - 30$

1. $3×4÷4 = 3÷4×（此处实际为连续运算） 3×1 =3$，$3 = 3$，故 $3×4÷4 = 3×1$；
2.$(48 - 36)÷3 = 12÷3 = 4$，$3×9×0 = 0$，$4 ＞ 0$，故$(48 - 36)÷3 ＞ 3×9×0$；
3.$70×8 = 560$，$71×8 = 568$，$560 ＜ 568$，故$70×8 ＜ 71×8$；
4.$178 - 84 - 33 = 178 - 117 = 61$，$178 - (84 + 33) = 178 - 117 = 61$，故$178 - 84 - 33 = 178 - (84 + 33)$；
5.$8×3 = 24$，$5×8 - 30 = 40 - 30 = 10$，$24 ＞ 10$，故$8×3 ＞ 5×8 - 30$；
6.$27÷3 + 18 = 9 + 18 = 27$，$27 + 3×18 = 27 + 54 = 81$，$27 ＜ 81$，故$27÷3 + 18 ＜ 27 + 3×18$；
7.$8÷4÷2 = 2÷2 = 1$，$8÷(4×2) = 8÷8 = 1$，故$8÷4÷2 = 8÷(4×2)$；
8.$430 - 184 + 75 = 246 + 75 = 321$，$430 - 184 - 75 = 246 - 75 = 171$，$321 ＞ 171$，故$430 - 184 + 75 ＞ 430 - 184 - 75$；
9.$12×2×5 = 24×5 = 120$，$12×5×2 = 60×2 = 120$，故$12×2×5 = 12×5×2$；
10.$28 + 3×30 = 28 + 90 = 118$，$28×3 - 30 = 84 - 30 = 54$，$118 ＞ 54$，故$28 + 3×30 ＞ 28×3 - 30$。

3. 在括号里填上合适的数。
()×4×2 = 480 (15 + 21)÷() = 4
756 - () + 211 = 600 () + 424 - 378 = 566
()×8 + 314 = 378 ()÷7 + 668 = 672

60，9，367，520，8，28

1. $480÷2÷4=60$，所以括号填60。
2. $(15 + 21)÷4=9$，所以括号填9。
3. $756 + 211 - 600=367$，所以括号填367。
4. $566 + 378 - 424=520$，所以括号填520。
5. $(378 - 314)÷8=8$，所以括号填8。
6. $(672 - 668)×7=28$，所以括号填28。