so the total price of a Textbook is $40 which is 100% and the tax is 10% so you need to find tax from the price of the textbook which is 10% of the price of the textbook then add the price of the textbook with the tax amount which is the final cost .
The first fraction is between 27 and 28, closer to 28. The second fraction is between 3 and 4, closer to 4. Compatible numbers in division are numbers that can be divided mentally. 28 divided by 4 is 7. The quotient will be around 7.
