### Pizza Portions

My friends and I love pizza. Can you help us share these pizzas equally?

### Pies

Grandma found her pie balanced on the scale with two weights and a quarter of a pie. So how heavy was each pie?

### Red Balloons, Blue Balloons

Katie and Will have some balloons. Will's balloon burst at exactly the same size as Katie's at the beginning of a puff. How many puffs had Will done before his balloon burst?

# Balance of Halves

### Why do this problem?

Whether this problem is done with a balance or with pencil and paper, there is more to it than just doing addition. Although addition and subtraction are involved, you are likely to find the children using all sorts of language associated with these two operations and one of the main points here is to establish a balance or equivalence as well as "equals". Some pupils are not so readily used to coming across situations like $3 + 5 = 6 + 2$, for example. You could use this activity to introduce some algebraic ideas, by encouraging the class to articulate what they are trying to find in a general sense. For example "$7$ balances two other numbers", or "$7$ = 'something' add 'something'"or "$7$ = ? $+$ ?". This will help them to get the idea that they are finding different numbers which fit this criterion - not just one answer.

### Key questions

How might you start?
How might you record your thinking?
How do you know you've got all the possibilities?

### Possible extension

As the question suggests, some learners might like to look at a balance involving other fractions.

### Possible support

Children might like to try Getting the Balance instead.