Decimal Operations to Hundredths
A 50-minute Grade 5 lesson on all four operations with decimals, where lining up the place values matters more than lining up the decimal points.
Decimal Operations to Hundredths is a free 50-minute Grade 5 maths lesson plan for Common Core standard 5.NBT.B.7 — do all four operations with decimals. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 5
- Length:
- 50 minutes
- Standard:
- 5.NBT.B.7
Grade 5 · Number & Operations in Base Ten
5.NBT.B.7
Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value.
Objective
Students will be able to add, subtract, multiply and divide decimals to hundredths using place value reasoning.
Students are successful when they can
- Aligns place values when adding and subtracting decimals.
- Multiplies a decimal by a whole number and places the point by estimating.
- Divides a decimal by a whole number.
What you need
- Place value charts extended to hundredths
- Hundred grids for modelling
- Calculation cards
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — which is bigger?
6 min- Compare 0.4 and 0.35, then 2.5 and 2.05.
- Reading the place values aloud settles both, and that habit runs through the lesson.
Teach — same places, same column
15 min- Add 3.6 + 2.45. Write them with the place values aligned: tenths under tenths, hundredths under hundredths.
- Fill the empty hundredths place on 3.6 with a zero. It changes nothing and makes the columns complete.
- Add: 6.05. Say why the alignment matters — you are adding tenths to tenths, never tenths to hundredths.
- Subtract 5.2 − 1.47 the same way, filling in 5.20 first.
- Multiply 2.4 × 3. Estimate: about 2.5 × 3 is 7.5. Calculate 24 × 3 = 72, and the estimate places the point: 7.2.
- Divide 6.4 ÷ 4. Estimate about 1.5. Calculate 64 ÷ 4 = 16, so 1.6.
“Line up the places, not the digits. And when you multiply or divide, estimate first — the estimate is what tells you where the point goes.”
Guided practice — estimate then compute
14 min- Pairs write every calculation with the place values aligned and empty places filled with zeros.
- For every multiplication and division they estimate before calculating.
- The estimate is used to place the decimal point rather than a rule about counting places.
Independent practice
12 min- Students complete a decimal operations page.
- Answers a factor of ten out are decimal point errors and the estimate would have caught every one of them.
Close
3 min- Give 0.6 × 4 and ask for the estimate before the answer.
- A bit over 2, so 2.4 and not 24 or 0.24.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Adds 3.6 + 2.45 as 3.6 + 2.45 with the digits right-aligned, giving 6.01 or similar.
Why: Whole number addition aligns from the right, and that habit has been carried over. The decimal point has not been used as the anchor.
Fix: Write both numbers on a place value chart. Tenths sit under tenths because they are the same kind of thing.
Places the decimal point by a remembered rule and gets 0.72 for 2.4 × 3.
Why: The rule about counting decimal places has been half-remembered and applied without a sanity check.
Fix: Estimate first. Two and a bit, three times, is about seven. That rules out 0.72 and 72 before any rule is needed.
Says 2.05 is larger than 2.5 because 05 has more digits than 5.
Why: The digits after the point are being read as a whole number rather than by place.
Fix: Read both as words: two and five hundredths against two and five tenths. The words carry the place and the digits do not.
If they are not there yet
- Fill every empty decimal place with a zero before calculating, so all numbers have the same number of places.
- Model additions on hundred grids before doing them in columns.
If they finish early
- Multiply a decimal by a decimal and reason about why the answer is smaller than both.
- Divide a decimal by a decimal by scaling both up first.
- Solve a two-step money problem involving decimals.
Exit ticket
Work out 4.7 + 2.36 and 3.2 × 4. Estimate the second before calculating.
What to look for: 7.06 and 12.8. An answer of 7.03 or 4.93 to the first means the columns were right-aligned; 128 or 1.28 to the second means the estimate was skipped.
Printable practice for 5.NBT.B.7
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Add DecimalsWork out each answer.
- Subtract DecimalsWork out each answer.
Questions about Decimal Operations to Hundredths
How long does the Decimal Operations to Hundredths lesson take?
50 minutes, split across 5 timed sections: warm-up 6 min, teach 15 min, guided practice 14 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Decimal Operations to Hundredths teach?
CCSS.MATH.CONTENT.5.NBT.B.7 — 5.NBT.B.7, Number & Operations in Base Ten for Grade 5: “Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value.” In plain terms, do all four operations with decimals.
What do I need to teach this lesson?
Place value charts extended to hundredths, hundred grids for modelling, calculation cards and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: adds 3.6 + 2.45 as 3.6 + 2.45 with the digits right-aligned, giving 6.01 or similar; places the decimal point by a remembered rule and gets 0.72 for 2.4 × 3 and says 2.05 is larger than 2.5 because 05 has more digits than 5. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Work out 4.7 + 2.36 and 3.2 × 4. Estimate the second before calculating.” 7.06 and 12.8. An answer of 7.03 or 4.93 to the first means the columns were right-aligned; 128 or 1.28 to the second means the estimate was skipped. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Decimal Operations to Hundredths?
Yes — 2 printable 5.NBT.B.7 worksheets, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Decimal Operations to Hundredths free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 5 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-05. Aligned to 5.NBT.B.7 of the Common Core State Standards for mathematics.