Listen to full audio with synchronized glowing sentence tracking, or click any sentence to listen instantly
| Operation | Key Signal Words | Typical Word Problem Question | Equation Form |
|---|---|---|---|
| Addition (+) | Total • Sum • Altogether • Combined • In all | 'What is the total number of items?' | Part + Part = Total |
| Subtraction (-) | Remaining • Left • Difference • How much more • Fewer | 'How many items are left?' | Total - Part = Remainder |
| Multi-Step (+ and -) | Earned then spent • Bought then sold • Donated then distributed | 'How much money/items remain at the end?' | (Start + Added) - Taken = End |
Scenario: A store has 12,000 laptops. In January it sold 3,450 laptops, and in February it sold 4,120 laptops. How many laptops remain?
Method 1 (Sequential Subtraction): 12,000 - 3,450 = 8,550 ➔ 8,550 - 4,120 = 4,430.
Method 2 (Combine then Subtract): Total Sold = 3,450 + 4,120 = 7,570 ➔ 12,000 - 7,570 = 4,430.
• Never leave an answer as an isolated number! Always append the unit: 4,430 laptops.
• Check: If you started with 12,000 and sold items, the answer MUST be less than 12,000.
Essential Mathematical Concepts & Vocabulary (12 Terms)
Official mathematical definitions, computational rules, and model examples
How to translate an entire story problem into a single elegant mathematical sentence!