How can estimating products you to place the decimal correctly?

Sara bought a pair of pants that were on sale for 30 percent off of the original price. if the original price of the pants was $29, what was the sales price of the pants?

Which of the fallowing best completes the sequence 5,10,15, a) 30 b) 22 c)25 d)35

Use set builder notation to represent the following set: { -3, -2, -1, 0}