Calculate \( 12 \times 15 \) by changing the numbers into friendlier numbers as we saw in the videos. Show how you work it out - type out your methods using the number keys on your computer here: Please type your response here.

6. Six classes, each with 38 pupils, went on an excursion. If one teacher way required to supervise 15 pupils, how many teachers were needed on the excursion?

166. En una actividad de integración participan 96 nifias y 112 niños. Hay que formar grupos con igual cantidad de integrantes, de tal forma que cada grupo renga la misma cantidad de nifios y la misma cantidad de nifas, Cuíl es la mayor cantidad de grupos que se puede formar y como estanán conformados?

9) \( \frac{(-3)^{6} \cdot 27^{3}}{81^{2} \cdot 243}= \)

1. \( 12 \frac{3}{2} \) of a sum of moncy is \( \$ 60 \). What is the sum of money? \( \begin{array}{llll}\text { (A) } \$ 7.50 & \text { (B) } \$ 20.83 & \text { (C) } \$ 72.50 & \text { (if) } 5480.00\end{array} \) ; 2. There are 40 students in a class. Boys make up \( 40 \% \) of the class. If \( 25 \% \) of the boys wear shirts jacs, how many boys wear shirt jacs? \( \begin{array}{llll}\text { (2) } 4 & \text { (B) } 10 & \text { (C) } 16 & \text { (D) } 30\end{array} \)

5. Box \( A \) has a mass of \( 3 \frac{3}{8} \mathrm{~kg} \). The mass of Box \( B \) is \( \frac{5}{6} \) the mass of Box \( A \). How much heavier is Box \( A \) than Box \( B \) ?