2-Digit ± 1-Digit worksheets for Grade 1 (Elementary School)

This unit practices adding or subtracting in the ones place while the tens place stays untouched. It splits into addition without carrying and subtraction without borrowing, and gathers only forms such as 24 + 3 and 38 - 5, where nothing crosses into the next place.

Answering 54 for 24 + 3 shows a place-value mix-up, with the single-digit number added to the tens. A changed tens digit in the answer identifies this pattern. In Word Problems, children sometimes add the two numbers when asked what is left, producing an answer with too many digits.