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Writing Fractions as Decimals

A 50-minute Grade 4 lesson on decimal notation for tenths and hundredths, where the decimal point is introduced as the marker that says where the whole numbers stop.

Writing Fractions as Decimals is a free 50-minute Grade 4 maths lesson plan for Common Core standard 4.NF.C.6 — write fractions as 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 4
Length:
50 minutes
Standard:
4.NF.C.6

Grade 4 · Number & Operations — Fractions

4.NF.C.6

Use decimal notation for fractions with denominators 10 or 100.

Objective

Students will be able to write fractions with denominators of 10 or 100 in decimal notation and read them correctly.

Students are successful when they can

  • Writes 7/10 as 0.7 and 43/100 as 0.43.
  • Writes 7/10 as 70/100 and 0.70, and explains why they are equal.
  • Reads 0.43 as forty-three hundredths, not zero point forty-three.

What you need

  • Hundred grids for shading
  • Place value charts extended to hundredths
  • Number lines from 0 to 1 marked in tenths
  • The printable practice sheet linked at the end of this plan

The lesson

Warm-up — shade the grid

6 min
  1. Shade 3/10 of a hundred grid by colouring three full columns.
  2. Ask how many small squares that is. Thirty out of a hundred, and the two names are already in the room.

Teach — a new column, one tenth the size

15 min
  1. Extend the place value chart rightwards. After the ones comes a place worth one tenth, then one hundredth.
  2. The rule is the same as always: each place is a tenth of the one on its left.
  3. Write 7/10 in the tenths column: 0.7. The zero says there are no whole ones.
  4. Write 43/100 as 0.43. Four tenths and three hundredths — read it that way, not as a pair of digits.
  5. Shade 7/10 and 70/100 on two grids. Identical shading, so 0.7 and 0.70 are the same number.
  6. Convert 1/2 by rewriting it as 5/10, then 0.5. Not every fraction has a tenths form, and that is worth saying.
“Read it as tenths and hundredths, not as point four three. The words tell you what the number is worth; the digits alone do not.”

Guided practice — three forms

14 min
  1. Pairs write each quantity three ways: as a fraction, as a decimal, and shaded on a grid.
  2. They convert tenths to hundredths and check the shading matches.
  3. Then they order a mixed set of decimals and fractions on a number line.

Independent practice

12 min
  1. Students complete a decimals page.
  2. 0.7 written for 7/100 is the diagnostic error — the digit went into the wrong column.

Close

3 min
  1. Ask which is larger, 0.3 or 0.29, and why.
  2. Three tenths against twenty-nine hundredths. Reading the words settles what counting the digits does not.

What goes wrong, and why

Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.

Says 0.29 is larger than 0.3 because 29 is larger than 3.

Why: The digits after the point are being read as a whole number, which is how every other number has been read.

Fix: Shade both on hundred grids. Thirty squares against twenty-nine. The comparison is decided by looking, and the reading habit follows.

Writes 7/100 as 0.7.

Why: The numerator has been placed immediately after the decimal point without counting the places the denominator requires.

Fix: Use the place value chart. Hundredths is the second place, so the 7 goes there and the tenths place needs a zero to hold it.

Says 0.7 and 0.70 are different numbers.

Why: The extra digit looks like extra quantity, and in whole numbers adding a digit always means more.

Fix: Shade both on identical grids. Seven columns and seventy squares are the same shading, so the numbers are equal.

If they are not there yet

  • Work with tenths alone until the notation is secure, then introduce hundredths.
  • Shade a grid for every number, so the decimal always has a picture attached.

If they finish early

  • Convert fractions with denominators of 2, 4, 5 and 20 by finding an equivalent over 100.
  • Add two decimals to hundredths using the grid.
  • Explain why 1/3 cannot be written exactly as tenths or hundredths.

Exit ticket

Write 9/10 and 9/100 as decimals. Which is greater, 0.4 or 0.38?

What to look for: 0.9, 0.09, and 0.4. Both written as 0.9 means the place was not counted; choosing 0.38 means the digits after the point were read as a whole number.

Printable practice for 4.NF.C.6

Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.

Questions about Writing Fractions as Decimals

How long does the Writing Fractions as Decimals 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 Writing Fractions as Decimals teach?

CCSS.MATH.CONTENT.4.NF.C.6 — 4.NF.C.6, Number & Operations — Fractions for Grade 4: “Use decimal notation for fractions with denominators 10 or 100.” In plain terms, write fractions as decimals.

What do I need to teach this lesson?

Hundred grids for shading, place value charts extended to hundredths, number lines from 0 to 1 marked in tenths 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: says 0.29 is larger than 0.3 because 29 is larger than 3; writes 7/100 as 0.7 and says 0.7 and 0.70 are different numbers. 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: “Write 9/10 and 9/100 as decimals. Which is greater, 0.4 or 0.38?.” 0.9, 0.09, and 0.4. Both written as 0.9 means the place was not counted; choosing 0.38 means the digits after the point were read as a whole number. 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 Writing Fractions as Decimals?

Yes — 2 printable 4.NF.C.6 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 Writing Fractions as Decimals 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 4.NF.C.6 of the Common Core State Standards for mathematics.