Mental Math Masters
10% of K80?
K8
80 ÷ 10 = 8.
What is a markup amount?
The amount added to direct cost to set a selling price.
Selling price = cost + markup amount.
Price K50, direct cost K40. Find gross profit per item.
K10
50 − 40 = 10.
Does the highest selling price always give highest total gross profit?
No
Units sold also affect total gross profit.
Name one possible customer for a notebook bundle.
For example, a scholar or family buying school supplies.
Accept any plausible customer with a reason.
25% of K60?
K15
60 ÷ 4 = 15.
Cost K40, markup 25%. Find the markup amount.
K10
40 × 0.25 = 10.
Price K35, direct cost K40. Find the gross loss per item.
K5 gross loss
35 − 40 = −5, a loss of K5.
Cost K40: A charges K50 and sells 12. Find total gross profit.
K120
(50 − 40) × 12 = 120.
A pouch costs K40. Add 50% markup and find gross profit per item.
Price K60; gross profit K20
Half of 40 is 20; add to cost.
50% of K140?
K70
140 ÷ 2 = 70.
Cost K60, markup 50%. Find the selling price.
K90
60 + 30 = 90.
Six items each earn K20 gross profit. Find the total.
K120
6 × 20 = 120.
Cost K40: B charges K60 and sells 10; C charges K80 and sells 4. Which wins?
B at K200
B: 20 × 10 = 200. C: 40 × 4 = 160.
Six notebook bundles cost K80 each and sell for K100 each. Total gross profit?
K120
(100 − 80) × 6 = 120.
Find 75% of K80 using mental shortcuts.
K60
50% is K40 and 25% is K20; add.
Cost K80, price K100. Find markup percentage.
25%
(100 − 80) ÷ 80 × 100 = 25%.
Ten baskets sell at K75 with K60 direct cost each. Find revenue and gross profit.
Revenue K750; gross profit K150
75 × 10 = 750; (75 − 60) × 10 = 150.
Cost rises to K50. B stays K60 with 10 sales; C stays K80 with 4. Which wins?
C at K120
B: 10 × 10 = 100. C: 30 × 4 = 120.
Same cost: low price earns K10 per unit and sells 12; high price earns K20 and sells 5. Which wins?
Low price: K120 versus K100
10 × 12 = 120; 20 × 5 = 100.
A cost of K80 rises by 25%. What is the new cost?
K100
Quarter of 80 is 20; 80 + 20 = 100.
Cost K40, price K60. Find markup and margin.
50% markup; 33⅓% margin
Gross profit K20; 20/40 = 50%, 20/60 = 33⅓%.
Gross profit K200; additional operating expenses K60. Find net profit.
K140
200 − 60 = 140, assuming all remaining expenses are included.
At K50 cost, how many K60 sales are needed to beat four K80 sales?
13 sales
C earns K120. B earns K10 each: 12 ties; 13 earns K130.
Why might a fair, profitable price change after costs rise? Use the pouch example.
Higher cost reduces unit gross profit. Recalculate expected total gross profit and consider customer response.
At cost K50, B earns K100 while C earns K120 with fixed sales. Higher prices may change demand in reality.