Writing expressions

Writing expressions

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This task is about describing algebra expressions using words.
The expression 3a2 + 2a can be written in words as:
  1. Square a
  2. Multiply this number by 3
  3. Multiply a by 2
  4. Add the number in ii) to the number in iii)

Question 1Change answer

a)  Write the expression 4(t + 3) in words:

Question 1Change answer

b)  Write the expression 2p(p - 1) in words:

Question 1Change answer

c)  Write the expression (3n + 1)(2n - 2) in words:
Task administration: 
This task can be completed with pen and paper or online (with NO auto marking).
Level:
5
Curriculum info: 
Maths, Number and Algebra, Equations and expressions
Keywords: 
algebraic expressions
Description of task: 
Students describe algebraic expressions in words.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Using symbols and expressions to think mathematically, sets 6-7
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

 

    

Y10 (10/00)

1 mark

a)

Statements which correctly state the expression in words and where the role of the brackets is explicit.
Examples:
•
 
•		 i)
ii)
i)
ii)
iii)		 Add 3 to t.
Multiply the result of i) by 4.
Multiply t by 4.
Multiply 3 and 4.
Add the results of i) and ii).

moderate

2 marks
(for all correct)
or
1 mark
(for 1 error or the last step missing)

b)

Statements which correctly state the expression in words and where the role of the brackets is explicit.
Examples:
•
 
 
•		 i)
ii)
iii)
i)
ii)
iii)		 Multiply p by 2p.
Multiply 2p by 1 or 2p by ⁻1
Subtract ii) from i) or add i) and ii)
Subtract 1 from p.
Multiply p by 2.
Multiply the results of i) by ii).

2 marks - difficult
 
1 mark - moderate

2 marks
(for all correct)
or
1 mark
(for 1 error or the last step missing)

c)

Statements which correctly state the expression in words and where the role of the brackets is explicit.
Examples:
•
 
 
 
 
•		 i)
ii)
iii)
iv)
v)
i)
ii)
iii)
iv)
v) 		 Multiply n by 3.
Add on 1 to the result of i).
Multiply n by 2.
Subtract 2 from the result of iii).
Multiply the result of ii) by the result of iv).
Multiply 3n by 2n.
Multiply 3n by ⁻2.
Multiply 2n by 1.
Multiply 1 by ⁻2.
Add i), ii) iii) and iv).

2 marks - very difficult

1 mark - difficult

NOTES:

  • The role of the brackets must be explicit. For example, "4 times t plus 3" is incorrect.
  • Multiplying by ⁻1 and adding is equivalent to multiplying by 1 and subtracting.
  • Accept statements which use expressions like "3t" instead of specifying "3 times t" in full.