This is a level 2 algebra strand activity from the Figure It Out series.
A PDF of the student activity is included.
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select an operation symbol to complete an equation
It is best to work through the first example with the class so that students understand that they must find a single operation that relates the numbers on the petal to the number at the centre of the flower. Note how all the petal numbers in this example can be expressed as two multiplied by another factor.
Students will need to apply their knowledge of the structure of the operations addition, subtraction, multiplication, and division. For example, with flower 37, the petal numbers are less than the centre number. This suggests that the operation is either division or subtraction since only whole numbers are involved. Students may realise that 37 is a difficult number to divide evenly because it is a prime.
Subtraction is the only plausible operation left.
As an extension, encourage students to create their own flowers. These may include fractions as well as whole numbers.
Answers to Activity
24 flower
Use the ÷ bag. 24 ÷ 4 = 6, 24 ÷ 12 = 2, 24 ÷ 2 = 12, 24 ÷ 8 = 3, 24 ÷ 3 = 8, 24 ÷ 6 = 4
3 flower Use the x bag. 3 x 6 = 18, 3 x 7 = 21, 3 x 1 = 3, 3 x 2 = 6, 3 x 3 = 9, 3 x 5 = 15, 3 x 4 = 12
37 flower
Use the – bag. 37 – 1 = 36, 37 – 23 = 14, 37 – 7 = 30, 37 – 16 = 21, 37 – 20 = 17, 37 – 28 = 9, 37 – 37 = 0
60 flower
Use the ÷ bag. 60 ÷ 2 = 30, 60 ÷ 3 = 20, 60 ÷ 6 = 10, 60 ÷ 5 = 12, 60 ÷ 10 = 6,
60 ÷ 12 = 5, 60 ÷ 4 = 15
5 flower
Use the + bag. 5 + 12 = 17, 5 + 3 = 8, 5 + 10 = 15, 5 + 15 = 20, 5 + 22 = 27,
5 + 6 = 11, 5 + 26 = 31