Shapes and Patterns
Primary 2 · Mathematics
Shapes and Patterns
Lesson 3 of 3
13 min
Let's begin
Mutesi sits with her grandmother, who is weaving an agaseke basket.
Black, yellow, black, yellow. The same two colours, again and again, all the way round.
"How do you know what comes next?" Mutesi asks. Her grandmother smiles. "It is a pattern. It tells you itself."
A pattern is something that repeats in the same order, again and again.
The bit that repeats is called the repeating part.
Look at Keza's beads: red, blue, red, blue, red, blue.
The repeating part is red, blue. She just says it over and over.
Do these two steps every time.
clap, clap, stamp, clap, clap, stamp, clap, clap, ___
The repeating part is clap, clap, stamp. We have already done clap, clap.
So the next one is stamp.
circle, square, triangle, circle, square, triangle, circle, ___
The repeating part is circle, square, triangle. We have just had circle.
After circle comes square.
Numbers make patterns too. To find the rule, ask: what did I do to get from one number to the next?
2, 4, 6, 8, ___
From 2 to 4 you add 2. From 4 to 6 you add 2. The rule is add 2.
8 + 2 = 10.
5, 10, 15, 20, ___
Each time you count on in fives. The rule is add 5.
20 + 5 = 25.
10, 9, 8, 7, ___
This one goes down. The rule is take away 1.
7 - 1 = 6.
Choose your repeating part, such as stone, leaf, leaf. Now lay it out three times:
stone, leaf, leaf, stone, leaf, leaf, stone, leaf, leaf.
Ask a friend what comes next. The answer is stone!
Take a sheet of paper. Fold it straight down the middle and press hard.
The two halves land exactly on top of each other. One half hides the other. They match.
The fold line is special. We call it a mirror line, because one half looks like the other half in a mirror.
Byiringiro folds a paper square from top to bottom. The halves match perfectly. Then he opens it and folds it from side to side. They match again!
So a square has more than one mirror line.
Write a big letter A on paper and fold it straight down the middle. The two halves cover each other exactly. A has a mirror line.
Now write a big letter R and fold it down the middle. Bits poke out on one side. The halves do not match. R has no mirror line.
So here is the test: fold on the line. If one half hides the other completely, with nothing sticking out, the halves match.
Things with matching halves are all around you: a butterfly, a leaf, a bottle, a door, and your own face.
Tip
Two little tricks to remember
For patterns: find the repeating part, then say it again.
For halves: fold it and look. If one half hides the other exactly, the fold line is a mirror line.
Now make your own pattern with stones and leaves outside, and fold a paper leaf to check its halves.
What you learned today
Quick check
yellow, black, yellow, black, yellow, ___
