Skip to content
MathAnvil
§ Arithmetic·Grades 5–6

Decimal Arithmetic Worksheets

Free PDF · Problems + answer key · Instant download

Easy

10 problems

Medium

20 problems

Hard

20 problems

Mixed

30 problems

Free printable decimal arithmetic worksheets with step-by-step answer keys. Every worksheet is uniquely generated so students never see the same problems twice. Topics covered range from decimal addition, 0.5 increments at the easy level through to mixed operations, estimation at the advanced level.

CCSS.5.NBTCCSS.6.NS

What is decimal arithmetic?

Decimal arithmetic involves performing addition, subtraction, multiplication, and division operations with decimal numbers. The fundamental principle requires aligning decimal points for addition and subtraction, while multiplication and division follow specific rules for decimal placement. These operations form the foundation for working with money, measurements, and precise calculations in mathematics.

Why it matters

Decimal arithmetic appears constantly in daily life through money calculations, measurements, and scientific data. A grocery bill totaling $47.83 requires decimal addition, while calculating a 15% tip on $28.50 involves decimal multiplication. Construction workers use decimal arithmetic when measuring lumber to the nearest 0.125 inches, and pharmacists calculate medication dosages in milligrams with 2-3 decimal places of precision. In advanced mathematics, decimal operations support algebra, geometry, and statistics. Students encounter decimal arithmetic in CCSS standards 5.NBT and 6.NS, progressing from basic tenths and hundredths comparisons to complex multi-step calculations. Scientific notation, percentage calculations, and unit conversions all rely on decimal arithmetic mastery. Financial literacy depends heavily on these skills, from calculating compound interest rates of 4.25% annually to comparing gas prices differing by $0.03 per gallon.

Common mistakes to watch for

  • Misaligning decimal points in addition produces errors like 12.3 + 4.56 = 16.86 instead of the correct 16.86 by treating it as 123 + 456.
  • Forgetting to count decimal places in multiplication leads to answers like 2.5 × 1.2 = 30 instead of 3.0 by placing the decimal incorrectly.
  • Moving the decimal point the wrong direction in division creates results like 48.6 ÷ 2.7 = 1.8 instead of 18 by shifting improperly.

Questions teachers ask

How do you line up decimal points for addition and subtraction?+
Write numbers vertically with decimal points directly aligned in the same column. Add zeros as placeholders if needed, so 12.3 + 4.56 becomes 12.30 + 4.56 with aligned decimal points.
What is the rule for decimal places in multiplication?+
Count the total decimal places in both factors, then place the decimal point that many places from the right in the product. For 2.5 × 1.2, count 2 total decimal places to get 3.00.
How do you divide with decimals?+
Move the decimal point in the divisor to make it a whole number, then move the decimal point in the dividend the same number of places. Divide normally and place the decimal point in the quotient.
Why do we align decimal points in addition but not multiplication?+
Addition combines place values directly (tenths with tenths, hundredths with hundredths), requiring alignment. Multiplication creates new place values through the distributive property, so decimal placement follows different rules based on factor decimal places.
How do you check if a decimal arithmetic answer is reasonable?+
Estimate by rounding to whole numbers first. For 47.9 × 21.44, round to 48 × 21 = 1008, which confirms the actual answer 1026.976 is reasonable since it's close to the estimate.
Generate worksheet →Free · No account · Unlimited

Pick a difficulty

Click any level to open the generator with that difficulty pre-selected.

Try a sample problem

Try it right now

Click “Generate a problem” to see a fresh example of this technique.

Learn the theory → Read our decimal arithmetic guide with worked examples.

Practice online → Interactive decimal arithmetic problems with instant feedback.