There is a special number in each of these envelopes.

When you get your envelope, open it and find out what your number is.

This number is the answer to a maths problem that YOU make up.

What is your problem?

Students are challenged to create their own number problems. This can require a deeper understanding than solving a given problem.

Some students may simply suggest an equation such as 2 + 3 = ? Some may be able to confidently embed an equation in a story context, and other students might readily suggest contextual problems that involve more than one step.

This open problem has students use their imaginations to create word problems of their own and to apply the mathematics that they are learning.

A series of similar problems span Level 1 to Level 5. These problems are Make Up Your Own, Level 2, Invent-A-Problem, Level 3, Create a Question, Level 4, and Working Backwards, Level 5.

You may find that this serves as a useful assessment task.

Numbers to go in the envelopes. Choose these as appropriate for your class.

Copymaster of the instructions (English)

Envelopes

### The Problem

There is a special number in each of these envelopes.

When you get your envelope, open it and find out what your number is.

This number is the answer to a maths problem that YOU make up.

What is your problem?

### Teaching Sequence

- Write a number for all to see. For example 8. Explain that this is the answer to a problem.
- Ask the students what two numbers add to make the number. Record the students ideas. (1 + 7, 2 + 6 etc.)
- Tell a story about a pair of numbers. (2 children are on the mat and 6 more come along. How many altogether are on the mat now?)
- Highlight/List key words for students to use as they write their own problems.
- Challenge children to work in pairs and suggest a number story (problem) of their own for the given number (8). Suggest what the problem could be about (cats, horses, subjects of current interest).
- Share and record stories of interest, have students check for each that the solution is the given number (8 in this case).
- Model and then challenge student pairs to make a problem that uses more than two addends (2 children + 1 child + 5 children = ? on the mat).
- Revisit the given problem and have students explain it in their own words.
- Have students work in pairs creating several word problems for their 'special number.'
- Support students with questions as they work on the problem.
- Students should return their special number to the envelope, keeping it secret, before sharing their problems for their classmates to solve.

**Extension**

Create subtraction problems for which the 'special' number is the difference.

**Solution**

The solutions depend on your class.