=(0.4×25)×( 125×0.8)

= 10× 100= 1000

1.24×8.3+8.3× 1.76

=8.3×( 1.24+ 1.76)

=8.3×3=24.9

9999× 100 1

=9999×( 1000+ 1)

=9999× 1000+9999× 1

= 10008999

14.8×6.3-6.3×6.5+8.3×3.7

=( 14.8-6.5)×6.3+8.3×3.7

=8.3×6.3+8.3×3.7

8.3×(6.3+3.7)

=8.3× 10

=83

1.24+0.78+8.76

=( 1.24+8.76)+0.78

= 10+0.78

= 10.78

933- 157-43

=933-( 157+43)

=933-200

=733

482 1-998

=482 1- 1000+2

=3823

I32× 125×25

=4×8× 125×25

=(4×25)×(8× 125)

= 100× 1000

= 100000

Percentage reciprocity

Conversion between percentages and decimals

(1) Decimal system: Delete the percent sign and move the decimal point to the left by two places. For example, 75% can be converted into 0.75.

(2) Decimal percentage: add a percent sign and move the decimal point to the right by two places. For example, 0.62 can be converted into 62%.