C1. Patterns and Relationships
Specific Expectations
Patterns
C1.1
identify and describe repeating, growing, and shrinking patterns, including patterns found in real-life contexts
- repeating patterns in real life:
- 24-hour clock
- appropriate warm-up and cool-down activities for daily physical activity
- morning routine
- growing patterns in real life:
- distance travelled as time passes
- growth of a plant over time
- number of pages they have read in their book over the week
- shrinking patterns in real life:
- height of a ball over successive bounces
- amount of sap as it boils down to make maple syrup
- height of a snowperson on a warm spring day
- Repeating patterns have a pattern core that is repeated over and over.
- In growing patterns, there is an increase in the number of elements or the size of the elements from one term to the next.
- In shrinking patterns, there is a decrease in the number of elements or the size of the elements from one term to the next.
- Many real-life objects and events can be viewed as having more than one type of pattern.
Note
- Growing and shrinking patterns are not limited to linear patterns.
Have students collect pictures or make diagrams of patterns that they find in real life and create a pattern wall. Have them describe the regularities that they see in any of the patterns. Some real-life examples may be viewed in more than one way. For example, a staircase can be viewed as a repeating pattern because the rise for each step is the same. The staircase can also be viewed as a growing pattern because each step goes up the same height so that the distance from the ground increases consistently. For each step down, the distance to the ground also decreases consistently.
C1.2
create and translate growing and shrinking patterns using various representations, including tables of values and graphs
- representations for a growing pattern:
- representations for a shrinking pattern:
- Growing patterns are created by increasing the number of elements or the size of the elements in each iteration (term).
- A growing pattern can be created by repeating a pattern’s core. Each iteration shows how the total number of elements grows with each addition of the pattern core.
- Shrinking patterns are created by decreasing the number of elements or the size of the elements in each iteration.
- In translating a pattern from a concrete representation to a table of values and a graph, each iteration of the pattern can be referred to as the term number, and the number of elements in each iteration can be referred to as the term value. The term value is dependent on the term number. The term number (x) is represented on the horizontal axis of the Cartesian plane, and the term value (y) is represented on the vertical axis. Each point (x, y) on the Cartesian plane is plotted to represent the pattern. In a table of values, the term number is shown in the left-hand column and the term value is shown in the right-hand column.
- A pattern’s structure is the same when a pattern is translated from one representation to another.
Note
- The creation of growing and shrinking patterns in this grade is not limited to linear patterns.
- For (x, y), the x-value is the independent variable and the y-value is the dependent variable.
Provide students with a repeating pattern such as the one below, which has a pattern core of three different colours of squares:
Have students take the repeating pattern and create a geometric representation that shows the increase in the number of tiles with each repetition of the pattern core. For example:
Next, have them create a table of values and a corresponding graph for this pattern. Ask them to make connections between all of the representations and to explain their thinking.
Ask students to create a growing pattern and a shrinking pattern using tiles, then exchange their patterns with a classmate. Have each student in a pair then create corresponding tables of values and graphs to represent their classmate’s patterns. After they have completed these tasks, set up a gallery walk, and ask students to give each other feedback on their representations.
C1.3
determine pattern rules and use them to extend patterns, make and justify predictions, and identify missing elements in repeating, growing, and shrinking patterns
- extending patterns in multiple directions:
- What does position 0 look like? What does position 5 look like?
- making near and far predictions:
- How many toothpicks are needed to show position 0?
- How many toothpicks are needed to show position 10?
- How many toothpicks are needed to show position 100? 99? 101?
- identifying missing shapes, numbers in sequences and tables of values, and points on a graph:
Position Number | Number of Toothpicks |
1 | 4 |
2 | 7 |
3 | |
4 | |
5 | 16 |
6 | |
7 | 22 |
- Patterns can be extended because they are repetitive by nature.
- Pattern rules are generalizations about a pattern, and they can be described in words.
- Patterns can be extended in multiple directions, showing what comes next and what came before.
- To make a near prediction about a pattern is to state or show what a pattern will look like just beyond the given representation of that pattern. The prediction can be verified by extending that pattern.
- To make a far prediction about a pattern is to state or show what a pattern will look like well beyond the given representation of that pattern. Often calculations are needed to make an informed prediction that can be justified.
- Identifying the missing elements in a pattern represented using a table of values may require determining the term number (x) or the term value (y).
- Identifying the missing elements in a pattern represented on a graph may require determining a point (x, y) within the given representation or beyond it, in which case the pattern will need to be extended.
- The algebraic expression that represents a linear growing pattern is also referred to as the general term or the nth term. It can be used to solve for the term value or the term number.
Note
- Determining a point within the graphical representation of a pattern is called interpolating.
- Determining a point beyond the graphical representation of a pattern is called extrapolating.
Provide students with a pictorial representation showing the first four positions of a growing pattern:
Have them show positions 0 and 5 and explain the rule that they used to determine each. Ask them to represent the pattern in a table of values and plot it on a graph.
Ask students to find missing elements in and extend shrinking patterns such as the following:
Ask them to describe the change from one position to the next.
Have students make and test predictions about patterns represented in various ways. For example:
- given a graphical representation, such as:
- Ask students to represent the pattern using tiles.
- Ask students to predict how many tiles are needed for position 6. Have them verify their prediction. (They could extend either their tile pattern or the graph.)
- Ask students if it is possible to show a position in this pattern using 36 tiles, and ask them to explain why or why not.
- given a concrete representation, such as:
- Ask students to identify and describe the pattern core.
- Ask students to imagine that they had to extend the pattern so that it had 10 repeats of the core. How many:
- yellow hexagons are needed?
- green triangles are needed?
- blue squares are needed?
- Ask students to justify their responses.
- Ask students to imagine that they had to extend the pattern so that it had 10 repeats of the core. How many:
- Providing students with different types of representations of patterns with missing elements enables them to think critically about possible pattern rules based on the information they are given. For example, ask them to fill in the missing numbers of tiles in a table of values, such as:
Position Number | Number of Tiles |
1 | 3 |
2 | |
3 | |
4 | 12 |
5 | 15 |
6 |
Provide students with the following scenario. A community centre has tables in the shape of a hexagon and sets them up for events as shown below. There is enough space in the room to set up rows of up to six adjoining tables. If more seating is needed, then additional rows must be added:
- How many people can sit at four tables? Six tables?
- How many tables are needed for 30 people? 50 people?
C1.4
create and describe patterns to illustrate relationships among whole numbers and decimal tenths and hundredths
- number pattern to show the relationships between ones, tenths, and hundredths:
Sample 1:
3.71 = | 3 ones | + 7 tenths | + 1 hundredth |
3.71 = | 3 ones | + 6 tenths | + 11 hundredths |
3.71 = | 3 ones | + 5 tenths | + 21 hundredths |
3.71 = | 3 ones | + 4 tenths | + 31 hundredths |
3.71 = | 3 ones | + 3 tenths | + 41 hundredths |
3.71 = | 3 ones | + 2 tenths | + 51 hundredths |
3.71 = | 3 ones | + 1 tenth | + 61 hundredths |
3.71 = | 3 ones | + 0 tenths | + 71 hundredths |
Sample 2:
3.71 = | 3 ones | + 7 tenths | + 1 hundredths |
3.71 = | 2 ones | + 17 tenths | + 1 hundredths |
3.71 = | 1 ones | + 27 tenths | + 1 hundredths |
3.71 = | 0 ones | + 37 tenths | + 1 hundredths |
- number pattern to show the relationship between the addition and subtraction facts for 7 when applied to decimal hundredths:
5.00 + 0.07 = 5.07 | 5.07 − 0.07 = 5.00 |
5.01 + 0.06 = 5.07 | 5.07 − 0.06 = 5.01 |
5.02 + 0.05 = 5.07 | 5.07 − 0.05 = 5.02 |
5.03 + 0.04 = 5.07 | 5.07 − 0.04 = 5.03 |
5.04 + 0.03 = 5.07 | 5.07 − 0.03 = 5.04 |
5.05 + 0.02 = 5.07 | 5.07 − 0.02 = 5.05 |
5.06 + 0.01 = 5.07 | 5.07 − 0.01 = 5.06 |
5.07 + 0.00 = 5.07 | 5.07 − 0.00 = 5.07 |
- number pattern to show the relationship between multiplication and division facts for 7:
7 × 0 = 0 | 7 ÷ 0 = undefined |
7 × 1 = 7 | 7 ÷ 1 = 7 |
7 × 2 = 14 | 14 ÷ 2 = 7 |
7 × 3 = 21 | 21 ÷ 3 = 7 |
7 × 4 = 28 | 28 ÷ 4 = 7 |
7 × 5 = 35 | 35 ÷ 5 = 7 |
7 × 6 = 42 | 42 ÷ 6 = 7 |
7 × 7 = 49 | 49 ÷ 7 = 7 |
7 × 8 = 56 | 56 ÷ 8 = 7 |
7 × 9 = 63 | 63 ÷ 9 = 7 |
7 × 10 = 70 | 70 ÷ 10 = 7 |
- Patterns can be used to understand relationships among numbers.
- There are many patterns within the decimal number system.
Note
- Many number strings are based on patterns and on the use of patterns to develop a mathematical concept.
- The use of the word “strings” in coding is different from its use in “number strings”.
Provide students with a partial number pattern based on place value. Have them continue the pattern in as many ways as they can using ones, tenths, and hundredths. Support students in noticing that if they take away 1 tenth, for example, they need to add it back as 10 hundredths:
Sample 1:
3.71 = | 3 ones | + 7 tenths | + 1 hundredth |
3.71 = | 3 ones | + 6 tenths | + 11 hundreths |
. | . | . | . |
. | . | . | . |
. | . | . | . |
. | . | . | . |
. | . | . | . |
. | . | . | . |
Sample 2:
3.71 = | 3 ones | + 7 tenths | + 1 hundredth |
3.71 = | 2 ones | + 17 tenths | + 1 hundredth |
. | . | . | . |
. | . | . | . |
Look for opportunities to have students create their own number patterns to show a mathematical concept. For example, they might demonstrate how the addition and subtraction facts for 7 hold true when working with decimal hundredths, or they might demonstrate the pattern for multiplication and division by 7:
7 × 0 = 0 | 7 ÷ 0 = undefined |
7 × 1 = 7 | 7 ÷ 1 = 7 |
7 × 2 = 14 | 14 ÷ 2 = 7 |
7 × 3 = 21 | 21 ÷ 3 = 7 |
7 × 4 = 28 | 28 ÷ 4 = 7 |
7 × 5 = 35 | 35 ÷ 5 = 7 |
7 × 6 = 42 | 42 ÷ 6 = 7 |
7 × 7 = 49 | 49 ÷ 7 = 7 |
7 × 8 = 56 | 56 ÷ 8 = 7 |
7 × 9 = 63 | 63 ÷ 9 = 7 |
7 × 10 = 70 | 70 ÷ 10 = 7 |
Ask students to create a four-digit number that has two decimal places. Have them cover their number using counters on a Gattegno chart. (A sample Gattegno chart can be downloaded at BLM: Grade 5 C1.4 Gattegno chart.) Now ask students to:
- multiply their number by 10 and move their counters so that they represent the new number (each counter goes up a row, but stays in the same column);
- predict what would happen if they multiplied their new number by 10;
- verify their prediction and move their counters to the new position;
- determine how they can get their counters back to the original positions using division;
- move the counters representing their original number up two rows using division.
Continue having students explore the patterns of multiplying (and dividing) by 10, 100, and 1000 and by 0.1 and 0.01, and support them in making generalizations about the results.
Ask students to use the following chart and rules to make 80 in as many ways as they can:
- Use a number from column A.
- Use an operation from column B.
- Use a number from column C.
A | B | C |
0.8 |
× ÷ |
0.01 |
8 | 0.1 | |
80 | 1 | |
800 | 10 | |
8000 | 100 | |
80 000 | 1000 |