d) 7,480
Combining the methods taught in this book creates endless possibilities. Experiment for yourself.
Note to parents and teachers
This chapter introduces the concept of positive and negative numbers. We will simply refer to them as plus and minus numbers
throughout the book.
These methods make positive and negative numbers tangible. Children can easily relate to the concept because it is made visual.
Calculating numbers in the eighties using double multiplication develops concentration. I find most children can do the calculations
much more easily than most adults think they should be able to.
Kids love showing off. Give them the opportunity.