2.① multiplication and division, addition and subtraction ② multiplication and addition 354 105⑤ 372⑥ 4709⑦ 4 ⑧ 270

Third, 1B2B3A4C

Four. 259 1850 18 4070 345 747

Five, ① (568+34) ÷ (70-56) = 43

②5 12÷ 16×4+280=408

③864÷32+ 18× 15=297

Six, ①80+80+20+80×2=340 (tree)

② 2050+2050× 2- 1200 = 4950 (unit)

③ (55-50) × 2× 7 = 70 (pieces)

④ 240 ÷ 6-240 ÷ 8 = 10 (hours)

⑤ (170-40× 2) ÷ (2+1) = 30 (bag)

⑥126 ÷ 2× 3-13 =176 (cm) The test question "Four Operation Test Questions and Answers in Unit 1, Volume 2, Grade 4 Mathematics, People's Education Press" comes from Feifei.