To round 8.456 to the nearest tenth consider the hundredths’ value of 8.456, which is 5 and equal or more than 5. Therefore, the tenths value of 8.456 increases by 1 to 5.
21.78, take and multiply 2.79 by 5 ( there are 5 week days), and add the 7.83 once because it is the price for the two coffees. So weekly he spends roughly 21.78 on coffees
