Free interactive math game: Subtract from Round — 500 − 168. Part of the Addition & Subtraction category on MathKite.
Taken from the generator that powers this exercise. A fresh set appears every time the page is opened, and the printable worksheet holds ten of them.
Subtracting from a round number such as 100 or 1000, where the usual exchange runs across several columns of zeros.
Instead of exchanging repeatedly, subtract from one less and add one back, or count up from the smaller number to the round one.
For 300 - 50, count up from 50: fifty more reaches 100, and two hundred more reaches 300, giving 250.
Getting lost in the chain of zeros. Counting up avoids the exchange altogether.