# formTruncatingRemainder(dividingBy:) Replaces this value with the remainder of itself divided by the given value using truncating division. ``` mutating func formTruncatingRemainder(dividingBy other: Float) ``` ## Parameters `other` The value to use when dividing this value. ## Discussion Performing truncating division with floating-point values results in a truncated integer quotient and a remainder. For values `x` and `y` and their truncated integer quotient `q`, the remainder `r` satisfies `x == y * q + r`. The following example calculates the truncating remainder of dividing 8.625 by 0.75: ``` var x = 8.625 print(x / 0.75) // Prints "11.5" let q = (x / 0.75).rounded(.towardZero) // q == 11.0 x.formTruncatingRemainder(dividingBy: 0.75) // x == 0.375 let x1 = 0.75 * q + x // x1 == 8.625 ``` If this value and `other` are both finite numbers, the truncating remainder has the same sign as this value and is strictly smaller in magnitude than `other`. The `formTruncatingRemainder(dividingBy:)` method is always exact. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)