Answer:
The number of children in the class now = 21
Regrouping is needed for easier arithmetic operations
Step-by-step explanation:
The number of children in the ballet class = 16
Number of children that join = 5
The number of children in the class now = (The number of children in the ballet class) + (Number of children that join)
The number of children in the class now = 16 + 5
The number of children in the class now = 21
Regrouping is done in order to make it easier to carry out arithmetic operations. Therefore, regrouping is needed for easier arithmetic operations