Mental Math Subtraction (Example)

In this video, Luca is at a store wanting to buy a video game costing $58. He has $139 and needs to calculate how much money he will have left after the purchase. To simplify the subtraction, the numbers are adjusted: 139 is increased to 140, and 58 is increased to 59. The subtraction is then performed in two steps: first subtracting 140 from 139, resulting in 90, and then subtracting 9, leaving Luca with $81. This method demonstrates an easier way to handle subtraction by adjusting numbers.

How much money does Luca have before buying the video game?

• $58

• $81

• $139

• $140

What is the cost of the video game Luca wants to buy?

• $81

• $59

• $58

• $140

Why is 139 changed to 140 in the calculation?

• To confuse Luca

• To make subtraction easier

• To increase the total amount

• To decrease the cost of the game

What is the result after subtracting 140 from 140?

• 90

• 0

• 9

• 81

How much money does Luca have left after buying the game?

• $58

• $139

• $81

• $90