The Simple View of Reading is a formula created by Gough and Turner in 1986. Supported by research, the formula is as follows:

Decoding x Language Comprehension = Reading Comprehension

Decoding and Language Comprehension are given values between 0 and 1, representing 0-100%. When multiplied you get a Reading Comprehension value between 0 and 1. In this equation, Decoding is the ability to accurately and quickly read both familiar and unfamiliar words. These words can be singular or connected in passages. Being able to read text fluently is critical, as slow and halting reading makes it more difficult to remember and understand what was read. Language Comprehension is the ability to understand what others are saying, while Reading Comprehension is understanding passages of text. 

This formula can help to identify why children are having trouble understanding what they are reading. From here targeted interventions can be implemented.

Reference:

WETA Public Broadcasting. (2021). The simple view of reading. https://www.readingrockets.org/article/simple-view-reading