Adding Decimals Worksheet Generator - Math Worksheet Math Worksheet. Use our Decimals addition worksheets to practice adding decimals up to 4 digits in both vertical and horizontal format. Here you can generate decimal addition worksheets to Add 1 digit decimals, Add 2-digit decimals, Add 3-digit decimals and Add 4-digit decimals. The problems can be configured for 1, 2, 3 and 4 Digits on the ...