=(5.76+4.24)+( 13.67+6.33)

= 10+ 10

=20

Example 2, 37.24+23.79- 17.24

=37.24- 17.24+23.79

=20+23.79

=43.79

Example 3,4× 3.78× 0.25

=4×0.25×3.78

= 1×3.78

=3.78

Example 4: 125×246×0.8

= 125×0.8×246

= 100×246

=24600

Example 5, (2.5+ 12.5) × 40

=2.5×40+ 12.5×40

= 100+500

=600

Example 6, 3.68× 4.79+6.32× 4.79

=(3.68+6.32)×4.79

= 10×4.79

=47.9

Example 7.26.86× 25.66-16.86× 25.66

=(26.86- 16.86) ×25.66

= 10×25.66

=256.6

Example 8, 5.7× 99+5.7

= 5.7×(99+ 1)

=5.7× 100

=570

Example 9, 34×9.9

=34×( 10-0. 1)

=34× 10-34×0. 1

=340-3.4

=336.6

For example, 10,57×101.

=57×( 100+ 1)

=57× 100+57× 1

=5757

For example, 1 1, 7.8× 1. 1.

=7.8×( 1+0. 1)

=7.8× 1+7.8×0. 1

=7.8+0.78

=8.58

Example12,25× 32

=25×4×8

= 100×8

=800

For example, 13, 125×0.72.

= 125×8×0.09

= 1000×0.09

=90

Example14,87× 2/85

=(85+2) ×2/85

=85×2/85+2×2/85

=2+4/85

=2 4/85

Example15,56.5-3.7-6.3

=56.5-(3.7+6.3)

=56.5- 10

=46.5

Example16,32.6 ÷ 0.4 ÷ 2.5

=32.6÷(0.4×2.5)

=32.6÷ 1

=32.6

For example,16,86.7× 0.356+1.33× 3.56.

=8.67×3.56+ 1.33×3.56

=(8.67+ 1.33)×3.56

= 10×3.56

=35.6

For example, 17, 15.6 ÷ 4-5.6× 1/4.

= 15.6× 1/4-5.6× 1/4

=( 15.6-5.6)× 1/4

= 10× 1/4

=2 and 1/2

For example: 18,16/23× 27+16×19/23.

=27/23× 16+ 16× 19/23

= 16×(27/23+ 19/23)

= 16×2 cases 1, 5.76+ 13.67+4.24+6.33.

=(5.76+4.24)+( 13.67+6.33)

= 10+ 10

=20

Example 2, 37.24+23.79- 17.24

=37.24- 17.24+23.79

=20+23.79

=43.79

Example 3,4× 3.78× 0.25

=4×0.25×3.78

= 1×3.78

=3.78

Example 4: 125×246×0.8

= 125×0.8×246

= 100×246

=24600

Example 5, (2.5+ 12.5) × 40

=2.5×40+ 12.5×40

= 100+500

=600

Example 6, 3.68× 4.79+6.32× 4.79

=(3.68+6.32)×4.79

= 10×4.79

=47.9

Example 7.26.86× 25.66-16.86× 25.66

=(26.86- 16.86) ×25.66

= 10×25.66

=256.6

Example 8, 5.7× 99+5.7

= 5.7×(99+ 1)

=5.7× 100

=570

Example 9, 34×9.9

=34×( 10-0. 1)

=34× 10-34×0. 1

=340-3.4

=336.6

For example, 10,57×101.

=57×( 100+ 1)

=57× 100+57× 1

=5757

For example, 1 1, 7.8× 1. 1.

=7.8×( 1+0. 1)

=7.8× 1+7.8×0. 1

=7.8+0.78

=8.58

Example12,25× 32

=25×4×8

= 100×8

=800

For example, 13, 125×0.72.

= 125×8×0.09

= 1000×0.09

=90

Example14,87× 2/85

=(85+2) ×2/85

=85×2/85+2×2/85

=2+4/85

=2 4/85

Example15,56.5-3.7-6.3

=56.5-(3.7+6.3)

=56.5- 10

=46.5

Example16,32.6 ÷ 0.4 ÷ 2.5

=32.6÷(0.4×2.5)

=32.6÷ 1

=32.6

For example,16,86.7× 0.356+1.33× 3.56.

=8.67×3.56+ 1.33×3.56

=(8.67+ 1.33)×3.56

= 10×3.56

=35.6

For example, 17, 15.6 ÷ 4-5.6× 1/4.

= 15.6× 1/4-5.6× 1/4

=( 15.6-5.6)× 1/4

= 10× 1/4

=2 and 1/2

For example: 18,16/23× 27+16×19/23.

=27/23× 16+ 16× 19/23

= 16×(27/23+ 19/23)

= 16×2

=32