Problem
Jennie the old sheep dog is lazing around in the paddock near the house. She counts the number of animals in the paddock. There are 11 of them, pigs and ducks. Then her eye runs over the legs. She sees 28 legs.
How many ducks are there?

What is this problem about?
This problem uses the multiplication facts of 2 and 4. It also gives students the opportunity to combine the operations of addition and subtraction. As there are many ways to solve this problem it is accessible to a range of students.

Achievement Objectives
Number (Level 2)
- write and solve story problems which require a choice of any combination of the four arithmetic operations

Mathematical Processes
- devise and use problem solving strategies (guess and check, guess and improve, act it out, draw a picture)

Resources
equipment for acting out
paper for drawing
Blackline master of problem (English)
Blackline master of the problem (Maaori)

Specific Learning Outcomes
The children will be able to:
- solve a story problem using multiplication facts of 2 and 4.

Lesson Sequence

1. Read the problem to the class.
2. Ask the children to highlight the important information.
3. For beginning problem solvers you might like to use them to act out the problem.
4. Start with 4 children at the front of the room. Ask 2 of them to be pigs (on all 4's) while the other 2 stand (ducks). Ask the class to count the legs.
5. Ask the children to think about what would happen if you "turned" one of the pigs into a duck.  How many animals?  How many legs?
6. Brainstorm other ways to solve the problem – list possibilities on board (draw, equipment, guess)
7. Children solve the problem.
8. Sharing of solutions and the strategies used.

Extension for early finishers
Get the children to write and solve their own problems by changing the numbers of animals and legs.

Other contexts for the problem
Horses and riders
Tricycles and bicycles

Solution
3 pigs, 8 ducks