Reading and Writing Eight-Digit Numbers

Primary Seven Mathematics — Term I, Topic 2

Uganda National Curriculum Development Centre

What You Will Learn in This Lesson

By the end of this lesson you will be able to:

1. Identify the ten-millions column — the new column in P7
2. Read eight-digit numbers using the group-of-three method
3. Write eight-digit numbers correctly in words and in figures
4. Compare and order large numbers using place value

Your P6 Place Value Chart

Seven columns — you know all of these:

The largest seven-digit number is 9,999,999 (nine million, …)

The New Column: Ten Millions (TM)

What comes after 9,999,999? → 10,000,000

We add the TM column to the left:

The largest eight-digit number is 99,999,999

Number in the Chart: 53,406,712

One digit per column — no column left empty:

Reading by Grouping in Threes

Split at the commas: 53 | 406 | 712

"Fifty-three million, four hundred and six thousand, seven hundred and twelve."

Rule: read each group as a number, then say its group name.

Placeholder Zeros in 90,070,005 Explained

Zeros hold a column — write them, but never say their group name:

"Ninety million, seventy thousand and five."

From Figures to Words: 72,308,045

Split at the commas: 72 | 308 | 045

Writing the Number Out in Words

"Seventy-two million, three hundred and eight thousand, and forty-five."

Now try: write 48,200,063 in words in your exercise book.

Check: forty-eight million, two hundred thousand, and sixty-three.

From Words Back to Figures

"Fourteen million, six hundred thousand and thirty-seven"

Answer: 14,600,037

Spelling Drill for Tricky Words

Two words that are often misspelled:

Rule: "four" drops the U when it becomes "forty"

Write: forty-eight, eighty-four, forty thousand

Practise Now on Your Own

a) Write 35,060,019 in words.

b) Write "twenty million, four hundred and eight thousand, and ninety" in figures.

Work in your exercise book. Check your spelling.

Comparing Two Large Whole Numbers

Which is greater: 38,004,500 or 38,040,500?

Step 1: Place both numbers in the chart, aligned:

Scan from left to right — find the first column where digits differ.

The Left-to-Right Comparison Scan Method

At TTh: 4 > 0, so 38,040,500 > 38,004,500

Ordering: Arrange Smallest to Largest

Given this set — arrange in ascending order:

All five numbers start with 12 in TM–M. Where do they first differ?

Ordering: Worked Solution and Answer

Ascending order (smallest first):

1. 12,243,678 ← differs at HTh (2 < 3)
2. 12,345,678 ← T = 7, U = 8
3. 12,345,687 ← T = 8, U = 7
4. 12,345,876 ← differs at H (8 > 6)
5. 12,354,678 ← differs at TTh (5 > 4)

Misconception 1: Internal Zeros and Spelling

Error A — Internal zeros: always fill every column in the chart.

Error B — Spelling: forty (not fourty), eight (not eigth)

Misconception 2: Comparing by Leading Digit

Wrong: "9,000,000 > 12,500,000 because 9 > 1"

Why it's wrong: 12,500,000 has 8 digits; 9,000,000 has only 7 digits.

Rule: Count digits first.
More digits → larger number (for positive whole numbers).
Then scan left to right only when digit counts are equal.

Exit Question to Check Understanding

Write 67,030,408 in words.
Identify the place value of the digit 3.

Exit Question: Answer and Explanation

"Sixty-seven million, thirty thousand, four hundred and eight."

Digit 3 is in the Ten Thousands (TTh) column.
Its value is .

Summary of the Three Core Moves

Three core moves:

1. Extend the chart — TM sits left of M
2. Group in threes — read each group with its name
3. Scan left to right — stop at first differing column

Next lesson: Roman Numerals up to MM (whole-numbers-02)