Mathematics
Number concept, addition and subtraction
Subtraction
Educator section
Memorandum
1.
a) 40
b) 420
c) 1 780
d) 24 270
3. less 40 because 19 + 1 = 20 and 21 – 1 = 20
Puzzle
a) 41 and 42
b) 118 and 119
c) 88 and 89
d) 100 and 101
Leaner section
Content
Activity: to determine the output values for given input values [lo 2.3]
1. Below is an example of a flow diagram. The numbers on the left are called input values, and the answers you have to provide are called output values. See whether you can complete the flow diagram without the help of a calculator.
2. Use a pocket calculator to check you answers.
3. How could you calculate the answers WITHOUT first subtracting 19 and then 21?
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A PUZZLE
Consecutive numbers are numbers that follow directly after one another when you count, e.g. 22 and 23. Show whether you are able to figure out what the missing consecutive numbers are that will make the following number sentences true:
TIME TO DO SELF-ASSESSMENT
- Colour in the picture that is true for you:
Assessment
Learning Outcome 2: The learner will be able to recognise, describe and represent patterns and relationships, as well as to solve problems using algebraic language and skills.
Assessment Standard 2.3: We know this when the learner determines output values for given input values, using:
2.3.1 verbal descriptions;
2.3.2 flow diagrams.