Mathematics Standard • Year 11 • Module 3 • Lesson 6

Deductions and Net Pay

Build fluency in net pay calculations: identify deductions correctly, calculate super, distinguish employer cost from employee deductions.

Build · Skill Drill

1. Quick recall

Answer each question in the space provided. 1 mark each

Q1.1 Complete the net-pay formula:

Net pay = ______________ − ______________

Q1.2 Tick each item that is normally subtracted from gross pay when finding net pay (in standard HSC questions):

[ ] PAYG tax [ ] Union fees [ ] Salary sacrifice super [ ] Employer super guarantee

Q1.3 Write a 1-sentence reasonableness check that catches a sign error in any net-pay calculation.

Stuck? Revisit lesson § What Are Deductions? and the misconception box.

2. Worked example — net pay with multiple deductions

Follow each line. Every step has a reason on the right.

Problem. Kofi's gross fortnightly pay is $3,240.00. His deductions are: PAYG tax $712.00, union fees $38.50, salary sacrifice super $162.00. Calculate his net pay.

Step 1 — Sum the deductions.

Total = $712.00 + $38.50 + $162.00 = $912.50

Step 2 — Subtract from gross.

Net = $3,240.00 − $912.50 = $2,327.50

Step 3 — Reasonableness check.

$2,327.50 < $3,240.00 ✓

Net is less than gross — answer is reasonable.

Conclusion. Net fortnightly pay = $2,327.50.

3. Faded example — employer super contribution + total cost

Amara earns $1,860 per fortnight in ordinary time. Her employer pays superannuation at 11.5%. Calculate (a) the employer's super contribution, and (b) the total fortnightly cost to the employer. Fill the blanks. 3 marks

Step 1 — Convert the super rate to a decimal:

11.5% = ____________

Step 2 — Apply the rate to ordinary time earnings:

Super = $1,860 × __________ = $ ____________

Step 3 — Note the impact on Amara's pay:

Employer super (does / does not) reduce Amara's net pay. Circle one.

Step 4 — Total employer cost:

Total cost = $1,860 + $ __________ = $ ____________

Stuck? Revisit lesson § Worked Example 2 — Employer Super Contribution.

4. Graduated practice — deductions and net pay

Show your working in the space below each part. Keep dollar amounts to 2 decimal places.

Foundation — direct net/gross calculations (4 questions)

Q	Problem	Answer
4.1 1	Gross pay $1,300; deductions $245. Calculate net pay.
4.2 1	Gross weekly pay $1,756.00; net pay $1,218.40. Calculate the total deduction.
4.3 1	Ordinary fortnightly earnings $3,400; super rate 11.5%. Calculate the employer super contribution.
4.4 1	Gross pay $1,940; total deductions $490. Calculate net pay.

Standard — typical HSC difficulty (6 questions)

Show at least one line of substitution and clearly label your final answer with units.

4.5 A worker has gross weekly pay $1,680. Deductions are PAYG tax $322 and union fees $18. Calculate the net pay. 2 marks

4.6 An employee earns $2,240 per fortnight in ordinary time. Calculate (a) the employer super contribution at 11.5%, and (b) the total employer cost. 2 marks

4.7 A worker's gross weekly pay is $1,520. Deductions from pay are PAYG tax $286 and union fees $14.50. The employer also pays super at 11.5% of gross pay. Calculate (a) the worker's net pay and (b) the total employer cost. 3 marks

4.8 A worker's gross pay is $1,940. Deductions are tax $388.50, salary sacrifice super $75.00, and health insurance $26.50. Calculate the net pay. 2 marks

4.9 A worker's gross fortnightly pay is $3,240. Calculate the employer super contribution at 12% (the rate from 1 July 2025). 1 mark

4.10 An employee receives 38 ordinary hours at $31.50/hr and 5 hours overtime at time-and-a-half. Deductions are PAYG tax $398, salary sacrifice super $95, health insurance $42.80. Calculate gross and net pay. 3 marks

Extension — percentage deduction + total cost (2 questions)

4.11 A worker earns $1,950 per week. Deductions are: PAYG tax 22% of gross, salary sacrifice super $80 flat, union fees $12 flat. Calculate the net pay. 3 marks

4.12 An employer offers a job at $74,880 gross per year. The job also includes employer super at 11.5%. Calculate (a) the total annual cost to the employer (wages + employer super), and (b) the equivalent monthly employer cost. 3 marks

Stuck on 4.11? Calculate PAYG tax FIRST ($1,950 × 0.22), then sum with the flat deductions, then subtract from gross.

5. Self-check the easy 3

Tick the first three once you've checked your method works.

For 4.1 my net pay was smaller than gross — I subtracted (not added).

For 4.3 (super at 11.5%) I used 0.115 (not 1.15 or 0.0115).

I did not subtract employer super from gross when calculating net pay.

How did this worksheet feel?

Got it Partly Lost

What I'll revisit before next class:

Answers — Do not peek before attempting

Q1.1 — Net pay formula

Net pay = Gross pay − Total deductions.

Q1.2 — What to subtract

Ticked: PAYG tax, Union fees, Salary sacrifice super. NOT ticked: Employer super guarantee — that is paid on top of wages, not deducted from them.

Q1.3 — Reasonableness check

Net pay must be less than gross pay. If net > gross, you've added a deduction by mistake or classified an employer-paid item as an employee deduction.

Q3 — Faded example (employer super + total cost)

Step 1: 11.5% = 0.115.
Step 2: Super = $1,860 × 0.115 = $213.90.
Step 3: Does NOT reduce Amara's net pay (employer cost only).
Step 4: Total cost = $1,860 + $213.90 = $2,073.90.

Q4.1 — Net pay

Net = $1,300 − $245 = $1,055.00.

Q4.2 — Total deductions

Deductions = $1,756.00 − $1,218.40 = $537.60.

Q4.3 — Super at 11.5%

Super = $3,400 × 0.115 = $391.00.

Q4.4 — Net pay

Net = $1,940 − $490 = $1,450.00.

Q4.5 — Net pay with two deductions

Total deductions = $322 + $18 = $340.
Net = $1,680 − $340 = $1,340.00.

Q4.6 — Employer super + total cost

(a) Super = $2,240 × 0.115 = $257.60.
(b) Total employer cost = $2,240 + $257.60 = $2,497.60.

Q4.7 — Net pay + employer cost

(a) Total deductions = $286 + $14.50 = $300.50. Net = $1,520 − $300.50 = $1,219.50.
(b) Employer super = $1,520 × 0.115 = $174.80. Total employer cost = $1,520 + $174.80 = $1,694.80.

Q4.8 — Net pay with three deductions

Total deductions = $388.50 + $75.00 + $26.50 = $490.00.
Net = $1,940 − $490 = $1,450.00.

Q4.9 — Super at 12%

Super = $3,240 × 0.12 = $388.80.

Q4.10 — Full gross to net

Ordinary = $31.50 × 38 = $1,197.00.
OT rate = $31.50 × 1.5 = $47.25 → 5 hrs = $236.25.
Gross = $1,197.00 + $236.25 = $1,433.25.
Total deductions = $398 + $95 + $42.80 = $535.80.
Net = $1,433.25 − $535.80 = $897.45.

Q4.11 — Percentage + flat deductions

PAYG tax = $1,950 × 0.22 = $429.00.
Total deductions = $429.00 + $80.00 + $12.00 = $521.00.
Net = $1,950 − $521 = $1,429.00.

Q4.12 — Annual + monthly employer cost

(a) Employer super = $74,880 × 0.115 = $8,611.20. Total annual cost = $74,880 + $8,611.20 = $83,491.20.
(b) Monthly cost = $83,491.20 ÷ 12 = $6,957.60 per month.