Decimal Addition with Whole Numbers
Use this worksheet to teach decimal addition with whole numbers. Work through one example with your student before assigning independent practice.
Teaching notes for parents and teachers
Use this worksheet to teach decimal addition with whole numbers. Work through one example with your student before assigning independent practice.
How to teach it
Use a place-value chart to line up decimal points. Show how trailing zeros can make equivalent places easier to see. Model regrouping from hundredths to tenths just as you would from ones to tens.
Examples to explain together
Check by subtraction: 17.8 − 1.8 = 16.
Check by subtraction: 12.4 − 2.4 = 10.
If your student needs help
If your student lines up the right-hand digits instead of decimal points, label the place value of each digit before adding.
Check understanding
Have your student subtract an addend from the sum. Also compare the answer with an estimate using nearby whole numbers.
Make a practice set
Select the worksheet, answer key, or both. When both are selected, the answer key prints after the questions. Keep it separate if you want your student to work independently.
After your student finishes
Review one problem together. Ask your student to explain the steps, then use the answer key to check the result. Revisit a difficult step before assigning another set.
About Decimal Addition with Whole Numbers
Practice decimal addition with whole numbers. Focus on accuracy before speed. Use the space provided to record the steps you need.
How to practice
Line up decimal points so that ones, tenths, and hundredths match. Add trailing zeros if they help you see the places; this does not change a number. Add from the smallest place shown and regroup as needed. Put the decimal point in the sum directly below the other decimal points.
Examples to explain together
Check by subtraction: 17.8 − 1.8 = 16.
Check by subtraction: 12.4 − 2.4 = 10.
If your student needs help
Align decimal points, not the right-hand ends of the numbers. For example, a tenth must not be added to a hundredth merely because both digits happen to be last.
Check understanding
Subtract either addend from the sum. Estimate with nearby whole numbers to check the size of the answer.
Before independent practice
Work through one example together. Ask the student to explain one step, then try a few questions independently. Review the cause of an error before repeating the calculation. Compare the student’s written steps with the answer key where worked steps are provided; a correct answer alone does not show which strategy was used.