FP/KS1 Introducing Algorithms 3: ‘AND’

Rather than repeat the background information, if you have hit on this post for the first time, we suggest that you look at the FP/KS1 Introducing algorithms 1: ‘IF’ and ‘THEN’  and FP/KS1 Introducing Algorithms 2: ‘NOT’

Aim: We are assuming that children are now familiar with the syntax “If this..then this” and If this…then not this.   The next important concept is to understand that sometimes you want to specify that more than one condition (or variable) is present in order to achieve a third condition or outcome.  In other words, “If this AND this, then this”.

Activity: We started off by using “If you put your aprons on AND put newspaper on the table, then you can paint.” So far so good. They understood the syntax and they got to paint.

We talked a lot about their day-to-day experiences using similar logical constructions such as:

“If you eat your dinner AND your pudding then you can have sweets”

“If you put your pyjamas on AND get into bed, then you can have a story.” etc.

More interestingly for 5 year olds, we talked about rainbows as they had recently been learning about how they were formed. As a result we got..

“If sun AND rain, then rainbows”

We used the  upside-down V (capital Lambda) as the symbol . This is in common use in maths and in programming and children will come across it again when they do set theory.  The option is to use a dot, which is also used in programming to denote ‘and’. However, in maths it can also be used for multiplication or decimal place so the potential for confusion is very high – don’t go there! We would also say avoid the + symbol which is used in some programming languages.  Children will be using + in maths to represent addition, which is a rather different meaning of ‘and’.  In programming or logic, ‘and’ does not imply that we are adding two things together, rather that two conditions are present.  A subtle difference but an important one.

By the way, in the middle of this activity, the children spontaneously introduced negatives and multiple conditions as in  “If you put your pyjamas on and you do not clean your teeth and get into bed then you can’t have a story.”  In some cases they were over stretching their logical capabilities but it showed they had grasped the basics and were starting to think creatively.

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