9.34+2.87-5.34

12-3. 14+6.34

0.78×40×2.5

1.25×8.88

3.54×0.29-0.29×2.54

0.25×32× 12.5

7.5+2.5×7.5+2.5

0.8+0.25×0.8

56.4-9.98

4.2× 10. 1

3.2+6.4×3.2+6.4

0.4×(2.5+0.25)

45.85-3.27×5. 1

35.8×9.8+3.58×2

1. 1×9× 1. 1+ 1. 1× 1. 1

1.73+ 1.73×3.5+5.5× 1.73

15.73-(2. 17+0.73)- 1.83

12345× 1 1 23×99

123×25×4 25×32× 125

456×2× 125×25×4×5×8

15000÷ 125÷ 15 1200÷25÷4

360×40÷60 947+(372-447)-572

325÷25 175×34+ 175×66

1000-547 176+348+252+424

285+998 300-57-20-23

(675+36)+( 164-375)

1870-280-520 4995-(995-480)

4250-294+94 37-(543- 163)-57

9998+998+99+9+6

1966+ 1976+ 1986+ 1996+2006

Improvement exercises:

In addition, if one addend increases by 50 and the other addend decreases by 30, there is ().

In subtraction, if the minuend increases by 50 and the difference decreases by 20, then subtraction ().

In multiplication, if one multiplier is enlarged by 4 times and the other multiplier is reduced by 2 times, the product ().