Association law;

Law of multiplication and distribution;

Extracting common factors;

Split method.

1. Switching Law:

256+78-56=256-56+78=200+78=278?

450×9÷50=450÷50×9=9×9=8 1

2. The association rule:

73+58+27+42=(73+27)+(58+42)= 100+ 100=200

345-67-33=345-(67+33)=345- 100=245 789- 133+33=789-( 133-33)=789- 100=689

5 10÷ 17 ÷3=5 1÷( 17×3)=5 10÷5 1= 10 1200÷48×4= 1200÷(48÷4)= 1200÷ 12= 100

3. Multiplicative distribution law:

74 x( 10+5)= 74 x 10+74 x 5 = 740+370 = 1 100

45×( 10+2)=45× 10+45×2=450+90=540

4. Extract common factors:

35×78+22×35=35×(78+22)=35× 100=3500

28 x 62+38 x 28 =(62+38)x 28 = 100 x 28 = 2800

5. Split method:

32× 125×25=8×4× 125×25=(8× 125)×(4×25)= 1000× 100= 100000?

36×25=9×4×25=9×(4×25)=9× 100=900