BAB ARITMETIKA SOSIAL PART #1 (Penjualan, Pembelian, Untung, Rugi, dan Persentasenya)

Summary

This educational video explains social arithmetic concepts commonly taught in Grade 7, focusing on cost price, selling price, profit, loss, and their percentages. Through clear explanations and many real-life examples—such as sellers of porridge, meatballs, and satay—the instructor guides students to identify profit, loss, or break-even situations by analyzing word problems. The lesson emphasizes literacy skills for AKM-style questions, highlights common traps in percentage calculations, and demonstrates both standard and shortcut methods. Special attention is given to frequently mistaken problems, especially when determining the original cost price from a known selling price and profit or loss percentage.

Takeaways

• 😀 The lesson focuses on calculating profit, loss, and percentages related to buying and selling prices.
• 😀 Profit occurs when the selling price is higher than the buying price. The formula for calculating profit is: Selling Price - Buying Price.
• 😀 Loss happens when the buying price is higher than the selling price. The formula for calculating loss is: Buying Price - Selling Price.
• 😀 One example is Fatih buying a T-shirt for Rp100,000 and selling it for Rp120,000, resulting in a profit of Rp20,000.
• 😀 Another example shows Fikri buying a toy for Rp80,000 and selling it for Rp70,000, resulting in a loss of Rp10,000.
• 😀 In real-life scenarios, the key is to focus on the numbers related to buying and selling prices to determine profit or loss.
• 😀 The script includes literacy practice by presenting scenarios with additional context, such as Pak Subur selling bubur ayam and Pak Soso selling bakso.
• 😀 Pak Subur spent Rp1,000,000 on ingredients to make 130 portions of bubur ayam but only sold 110 portions, resulting in a profit of Rp100,000.
• 😀 Pak Soso, who sells bakso, faced a loss when he only sold 90 portions instead of 120, leading to a loss of Rp80,000.
• 😀 The lesson explains how to calculate percentages of profit or loss, where profit percentage is: (Profit ÷ Buying Price) × 100%.
• 😀 It also covers more advanced methods to calculate selling prices based on given profit or loss percentages, such as using 120% for profit and 75% for loss.

Q & A

What is the main topic discussed in the video script?

The video focuses on teaching arithmetic concepts related to business transactions, specifically profit, loss, cost price, selling price, and percentage calculations, which are commonly tested in national exams.

What is the correct method for calculating profit?

To calculate profit, subtract the cost price (harga beli) from the selling price (harga jual). The formula is: Profit = Selling Price - Cost Price.

What happens when the selling price is lower than the cost price?

When the selling price is lower than the cost price, it results in a loss. The formula for calculating loss is: Loss = Cost Price - Selling Price.

How do you calculate the percentage of profit?

The formula for calculating percentage profit is: Profit Percentage = (Profit / Cost Price) × 100%. This shows the profit as a percentage of the original cost price.

What is the formula for calculating percentage loss?

The formula for calculating percentage loss is: Loss Percentage = (Loss / Cost Price) × 100%. This gives the loss as a percentage of the original cost price.

What was the correct answer for the profit on a t-shirt bought for Rp100,000 and sold for Rp120,000?

The profit in this case is Rp20,000, calculated by subtracting the cost price (Rp100,000) from the selling price (Rp120,000).

What mistake do students commonly make when solving percentage profit/loss problems?

A common mistake is calculating the percentage profit or loss using the selling price instead of the cost price. This results in incorrect answers.

What is the key point when solving a question about profit or loss in a business transaction?

The key point is to always focus on the cost price as the base when calculating percentage profit or loss, as all formulas are based on the cost price.

How did Pak Subur, the seller of bubur ayam, make a profit despite selling less than he produced?

Pak Subur made a profit by selling 110 out of 130 portions, earning a total of Rp1,100,000 from sales, which was more than the Rp1,000,000 he spent on ingredients. His profit was Rp100,000.

How do you calculate the price when the profit percentage is given, and the cost price is known?

To calculate the selling price when the profit percentage is given, you multiply the cost price by (100% + profit percentage). For example, if the cost price is Rp100,000 and the profit percentage is 20%, the selling price is Rp120,000.