What can be calculated simply should be calculated simply (1) 6 / 7 - (3 / 10-1 / 7) + 7 / 10 (2) (1 / 2 + 5 / 12 × 2 / 3) △ 7 / 9 (3) 36 × 5 / 6 + 5 / 6 × 0.64 (4) 5x of 6 + 1 of 6 = 8 of 9 （5）0.69+0.53+2.47+0.31

What can be calculated simply should be calculated simply (1) 6 / 7 - (3 / 10-1 / 7) + 7 / 10 (2) (1 / 2 + 5 / 12 × 2 / 3) △ 7 / 9 (3) 36 × 5 / 6 + 5 / 6 × 0.64 (4) 5x of 6 + 1 of 6 = 8 of 9 （5）0.69+0.53+2.47+0.31

6 / 7 - (3 / 10-1 / 7) + 7 / 10
=6/7-3/10+1/7+7/10
=(6/7+1/7)+7/10-3/10
=1+7/10-3/10
=14/10
(1 / 2 + 5 / 12 × 2 / 3) △ 7 / 9
=(1/2+5/18)x9/7
=1/2x9/7+5/18x9/7
=9/14+5/14
=1
36 × 5 / 6 + 5 / 6 × 0.64
=5/6x(0.36+0.64)
=5/6x1
=5/6
5x of 6 + 1 of 6 = 8 of 9
5x/6=8/9-1/6
5x/6=13/18
x=13/15
0.69+0.53+2.47+0.31
=(0.69+0.31)+(0.53+2.47)
=1+3
=4