Question: John was sick for 3 days in a particular week. Choose the number sentence to calculate n, the number of days John was not sick in that week.
A ) 7n = 3 B ) 7 - 3 = n C ) 3n = 7 D ) 7 + 3 = n
Steps to derive
1 Let n be the number of days, John was not sick.
2 The number sentence can be written as, (Number of days, John was not sick) = (total number of days in a week) - (total number of days, John was sick).
3n = 7 - 3 [Substitute the values.]
4 So, the number sentence used to calculate the number of days, John was not sick is, 7 - 3 = n.
