Add and Subtract 3-Digit Numbers and Multiples of 100: Missing Numbers Worksheet

In add and subtract 3-digit numbers and multiples of 100 worksheet, students must find the missing number using the count-on or count back method or the relationship between addition and subtraction. This worksheet is about practicing with the horizontal format in which numbers are written side by side. To develop flexibility with numbers and operations, students need to have enough practice in this format and not just rely on the vertical/column method.