At the garden centre

This task is about rounding and multiplying prices.
 
Jackie was shopping at a garden centre. She estimated the cost of her purchases by:
  • rounding the cost of a single plant to the nearest ten dollars, and
  • multiplying it by the number of plants she wanted.
Write down Jackie's estimate for each group of items.

Question 1Change answer

a) 25 roses costing $12.50 each.  $ 
b) 12 trees costing $23.95 each.  $ 
c) Five sets of terracotta pots costing $74.75 per set.  $ 

Question 1Change answer

d)  Why is Jackie's method of estimating the total bill not very accurate?

Question 2Change answer

e)  How could she get a more accurate estimate while still using numbers that are easy to multiply in her head?