Addition strategies for third graders

Which rational number represents a decrease in water level from 8 feet to 6 feet?

A car requires 22 litres of petrol to travel a distance of 259.6 km. Find 1) the distance that the car can travel on 63 litres of petrol, 2) the amount that the car owner has to pay to travel a distance of 2013.2 km if a litre of petrol costs $1.99.

How do I solve a problem dealing with percentages? Example: 10% of $50.00 It's become very frustrating because google says this is the formula: Sale price = Original price * (1 - Percent off%) I really don't understand how the formula works.

What does x equal in 3x 81 = - 9?

Calculate the circumference of a beach ball whose air capacity is 22.7L. round the final answer to the nearest tenth of a metre.

Divide the following polynomials, then place the answer in the proper location on the grid. Write answer in descending powers of x. (2x3 + x4 - 6x2 + 11x - 10) (x2 + 2 - x)

What is 3.75 rounded to

A child takes a nap averaging three hours and gets an average of 12 hours of sleep at night. Nap time and night time sleep can each vary by 30 mins. What are the possible time lengths for the child's nap and night time sleep? ... ?

4x - 10 ≥ 22 or x - 5 < - 6

What does control for eximerment mean .