› $a = 10
10
› sprintf '%.f', $a += (100-10)/7
23
› sprintf '%.f', $a += (100-10)/7
36
› sprintf '%.f', $a += (100-10)/7
49
› sprintf '%.f', $a += (100-10)/7
61
› sprintf '%.f', $a += (100-10)/7
74
› sprintf '%.f', $a += (100-10)/7
87
› sprintf '%.f', $a += (100-10)/7
100

› $a = 10
10
› sprintf '%.f', $a += (100-10)/3
40
› sprintf '%.f', $a += (100-10)/3
70
› sprintf '%.f', $a += (100-10)/3
100