# Castle Douglas Primary and Early Learning and Childcare Centre # Expressions and Equations

Activity 1 – Functions Quiz

Focus – I have investigated how a function machine can be used to represent a single operation.

Resources – paper and pens

Design a function machine and use it to work out inputs and outputs (example below). Using the function machine to challenge other family members e.g. by keeping one piece of information hidden, e.g. by not giving the input, the function or the output. Activity 2 – Missing Number Quiz

Focus – I have explored what values make an equation balance or not.

Resources – paper and pens

Create some own true equations that involve several operations on each side of the equals symbol. (example below) From these, devise a quiz, by keeping one number hidden, to create missing-number statements. Share your quiz with a family member. Activity 3 – What’s Unknown

Focus – I can solve simple equations with letters representing unknown values using my known number facts.

Resources – paper and pen

Work together to solve these equations and explain to each other how you worked out your answer.

x + 9 = 12               s – 1 = 10                 3 = z – 11                5 + y = 7

8 = 2 + q                6 = n – 4                   r – 2 = 5                 6 = m + 6

When using multiplying in an equation there is no ‘x’ sign. The missing letter and number are written together

e.g.  3a = 24    3 multiplied by what (a) = 24    a = 8          e.g. 40=7b+5     Answer is 7 x 5 +5 =40   b = 5

Now try these

3x = 27                  5p = 25                      24= 6c                     8u = 40

4b+7 = 23             80 = 6z+20               6d-5=37                  9c+9=63 Activity 5 – Function Quiz.

Focus – I can work out the input or output values of a two-step function machine

Resources – pencil and paper

Design your own function machines and work out inputs and outputs. From these, devise a quiz, by keeping one piece of information
hidden, e.g. by not giving the input, the function or the output. Share your quiz with another family member or bring into school to share with a friend. Activity 6 – Order Order.

Focus – I can work out the input or output values of a two-step function machine

Resources – pencil and paper

Investigate the different outputs that can be generated by putting in the same inputs for functions that involve these three operations: × 2, + 1 and – 3.
For example, if the input is 5 and the function machine is + 1, × 2, – 3 then output is 9.  (5+1=6 then 6×2 = 12 then 12-3 = 9)

But if the function machine is – 3, + 1, × 2 the output is 6. (5-3=2 then 2 +1 = 3 then 3×2 = 6)
Investigate all possible variations of the three operations and make notes about what you discover. Discuss with a family partner. Activity 7 – Quiz Time.

Focus – I can create and simplify expressions using symbols and letters.

Resources – pencil and paper

Write an expression, e.g. 2m + 4m + 2 – 3m, and give four multiple-choice options for the simplified answer,

e.g.
(A) 9m + 2
(B) 6m + 2
(C) 3m + 2
(D) 8m – 3.

Do this for three expressions and then bring them into class to use in a quiz.

x + 9 = 12       + 9 = 12         x = 3

s – 1 = 10        11 – 1 = 10          s = 11

3 = z – 11        14 – 11 = 3          z = 14

5 + y = 7          5 + 2 = 7           y = 2

8 = 2 + q         2 + 6 = 8           q = 6

6 = n – 4         10-4 = 6            n = 10

r – 2 = 5          7-2 = 5             r = 7

6 = m + 6        0 + 6 = 6         m = 0

3x = 27            3 x 9 = 27         x =9

5p = 25            5 x 5 = 25        p = 5

24= 6c             6 x 4 = 24        c = 4

8u = 40           8 x 5 =40          u = 5

4b+7 = 23          23-7 = 16 and  4 x 4 = 16             b = 4               4 x 4 +7 =23

80 = 6z+20         80-20 = 60 and 6 x 10 = 60      z = 10             80 = 6 x 10 + 20

6d-5=37                5 + 37 = 42  and 6 x 7 = 42       d = 7               6 x 7 -5 = 37

9c+9=63            63-9 = 54    and 9 x 6 = 54           c = 6               9 x 6 + 9 = 54