Spraying roses

Spraying roses

Auto-markingPencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
This task is about working out rates and ratios.
Tony wanted to make up some spray for his roses. He followed the directions on the packet, as shown.
Rose Spray
 
Contents: 200 grams
 
Directions:
 1.  Mix three heaped tablespoons of powder into
      5 litres of water.
 2.  Stir thoroughly.

Answer the following questions.
You will need to remember that:
 
One heaped tablespoon = 5 grams   heaped-teaspoon.png
 
 

Question 2Change answer

a)  How many heaped tablespoons of powder will be in Tony's 200 g packet?
       tablespoons

Question 2Change answer

b)  How many litres of spray will Tony make from 12 heaped tablespoons of powder?
      litres

Question 2Change answer

c)  How many full 10 litre buckets of spray could Tony make from this packet?
      buckets
Task administration: 
This task can be completed with pencil and paper or online (with auto marking displayed to students).
Level:
5
Curriculum info: 
Maths, Geometry and Measurement, Measurement
Keywords: 
rates, weight, volume, conversion of units
Description of task: 
Students answer questions about mixing quantities of powder and water to make a spray for rose bushes.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Measurement sense, sets 7-8
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y10 (12/97)
a) 40 very easy
b) 20 easy
c) 6 (need 210 g for 7 buckets) difficult
 
 
Diagnostic and formative information: 
  Common error Likely calculation Likely misconception
b) 60 12 × 5 Assume 1 tablespoon makes 5 litres.
c) 6.66   Ignores that answer must be a whole number.
c) 2 20 ÷ 10 Calculates number of full buckets from 12 heaped tablespoons.