Hi bryanlovell, thanks for the question. With a closer look at the calculator screenshot, notice the capital "E" between 1.897 and 27. This is my favorite shorthand way of writing "times 10^". It has an advantage over typing "* 10^27" since the calculator understands that 1.897E27 should be treated as a single number. This means that when dividing by 1.897E27, the 10^27 factor stays in the denominator where it belongs with the 1.897 factor. To explain by example, for the problem $\dfrac{20}{10} = 2$, typing "20 / 1E1 = 2" which is correct, whereas "20 / 1 * 10^1 = 200" which is not the expected answer since the capital E wasn't used. Of course, one could type "20 / (1 * 10^1) = 2" to get the correct answer with brackets, but avoiding the trouble of typing those brackets is the whole point of the capital E shortcut.

I hope you enjoy the solutions,

Shaun

Hi bryanlovell, that's awesome! Thanks for sharing that!

Hi raffielliemarley, that's a fair question. Currently I'm accelerating coverage of more chapters by doing only the odds the first time through. After covering odds in every chapter I'll probably do all the evens, depending on survey results (https://www.surveymonkey.com/r/N5WX87Y) from students.

I hope the videos are helpful with your studies,

Shaun