Penjelasan dengan langkah-langkah:

1. 0,42 : 0,6 - 0,65 x 1/13 =

=>42/100:6/10 - 65/100×1/13

=( 42/100×10/6) - ( 65/100×1/13)

= 420/600 - 65/1300

= 7/10 -1/20

= 14/20 - 1/20

= 13/20 atau 65/100 atau 0,65

2. 2 - 0,68 + (1,25 : 0,5)

=> 2/1-68/100 + (125/100 : 5/10)

= 50/25-17/25 + (5/4 :1/2)

= 33/25+ ( 5/4 ×2/1)

= 33/25 + 10/4

= 132/100+ 250/100

= 382/100

= 191/50 = 3 41/59 atau 3,82

3. (0,4 x 1,26) +( 0,72 : 8)

=> (4/10×126/100) + (72/100 : 8/1)

= (504/1000)+ (72/100 × 1/8)

= 63/125 + 72/800

=63/25+9/100

=252/500+45/500

= 297/500 = atau 594/1000=0,594

4. (9 x 0,2) - (1,6 : 4) =

=>(9 ×2/10) - (16/10 : 4/1)

= 18/10 - (16/10×1/4)

= 9/5 - 16/40

=9/5 - 2/5

= 7/5 atau 14/10 atau 1,4