Learn on PengiSaxon Math, Intermediate 4Chapter 1: Lessons 1–10, Investigation 1

Lesson 7: Writing Numbers Through 999

In this Grade 4 Saxon Math lesson, students learn to write whole numbers through 999 using standard number words, including correct hyphenation for two-digit numbers greater than twenty and proper three-digit number naming without using the word "and." Students also practice converting between written word form and digit form, comparing whole numbers using place value, and arranging numbers in order from least to greatest.

Section 1

📘 Writing Numbers Through 999

New Concept

Whole numbers are the counting numbers and the number zero.

0,1,2,3,4,5,0, 1, 2, 3, 4, 5, \ldots

What’s next

Next, you’ll practice writing and comparing numbers up to 999, translating between digits and words.

Section 2

Whole numbers

Property

Whole numbers are the counting numbers and the number zero.

0,1,2,3,4,5,0, 1, 2, 3, 4, 5, \ldots

Example

The number 42 is a whole number. The number 987 is a whole number. The number 0 is a whole number.

Explanation

Imagine you're counting treasures in a chest—one, two, three... those are counting numbers! Now, what if the chest is empty? You'd have zero treasures. Whole numbers are simply all your counting numbers plus their buddy, zero. They represent complete items without any messy fractions or decimal parts involved, keeping your math clean and simple.

Section 3

Reading Math

Property

The names of two-digit numbers greater than twenty that do not end in zero are written with a hyphen.

Example

The number 51 is written as 'fifty-one'. The number 87 is written as 'eighty-seven'. The number 33 is written as 'thirty-three'.

Explanation

When you write out two-digit numbers in words, think of the hyphen as a special connector that holds the words together. For any number from twenty-one to ninety-nine (as long as it doesn't end in zero), you need this little dash to properly link the tens part and the ones part, like making 'seventy' and 'four' become 'seventy-four'.

Section 4

We do not use the word and when writing whole numbers.

Property

To write three-digit numbers, we first write the number of hundreds and then we write the rest of the number. We do not use the word and when writing whole numbers.

Example

The number 313 is written as 'three hundred thirteen'. The number 705 is written as 'seven hundred five'. The number 444 is written as 'four hundred forty-four'.

Explanation

When writing a number like 525, you should state it as 'five hundred twenty-five.' You must avoid sneaking the word 'and' in there, as in 'five hundred and twenty-five.' In the math world, the word 'and' is a secret password reserved for separating whole numbers from their decimal or fractional parts, so we save it for later use.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 1: Lessons 1–10, Investigation 1

  1. Lesson 1

    Lesson 1: Review of Addition

  2. Lesson 2

    Lesson 2: Missing Addends

  3. Lesson 3

    Lesson 3: Sequences

  4. Lesson 4

    Lesson 4: Place Value, Activity Comparing Money Amounts

  5. Lesson 5

    Lesson 5: Ordinal Numbers, Months of the Year

  6. Lesson 6

    Lesson 6: Review of Subtraction

  7. Lesson 7Current

    Lesson 7: Writing Numbers Through 999

  8. Lesson 8

    Lesson 8: Adding Money

  9. Lesson 9

    Lesson 9: Adding with Regrouping

  10. Lesson 10

    Lesson 10: Even and Odd Numbers

  11. Lesson 11

    Lesson 11: Investigation 1 Number Lines, Activity Drawing Number Lines

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

📘 Writing Numbers Through 999

New Concept

Whole numbers are the counting numbers and the number zero.

0,1,2,3,4,5,0, 1, 2, 3, 4, 5, \ldots

What’s next

Next, you’ll practice writing and comparing numbers up to 999, translating between digits and words.

Section 2

Whole numbers

Property

Whole numbers are the counting numbers and the number zero.

0,1,2,3,4,5,0, 1, 2, 3, 4, 5, \ldots

Example

The number 42 is a whole number. The number 987 is a whole number. The number 0 is a whole number.

Explanation

Imagine you're counting treasures in a chest—one, two, three... those are counting numbers! Now, what if the chest is empty? You'd have zero treasures. Whole numbers are simply all your counting numbers plus their buddy, zero. They represent complete items without any messy fractions or decimal parts involved, keeping your math clean and simple.

Section 3

Reading Math

Property

The names of two-digit numbers greater than twenty that do not end in zero are written with a hyphen.

Example

The number 51 is written as 'fifty-one'. The number 87 is written as 'eighty-seven'. The number 33 is written as 'thirty-three'.

Explanation

When you write out two-digit numbers in words, think of the hyphen as a special connector that holds the words together. For any number from twenty-one to ninety-nine (as long as it doesn't end in zero), you need this little dash to properly link the tens part and the ones part, like making 'seventy' and 'four' become 'seventy-four'.

Section 4

We do not use the word and when writing whole numbers.

Property

To write three-digit numbers, we first write the number of hundreds and then we write the rest of the number. We do not use the word and when writing whole numbers.

Example

The number 313 is written as 'three hundred thirteen'. The number 705 is written as 'seven hundred five'. The number 444 is written as 'four hundred forty-four'.

Explanation

When writing a number like 525, you should state it as 'five hundred twenty-five.' You must avoid sneaking the word 'and' in there, as in 'five hundred and twenty-five.' In the math world, the word 'and' is a secret password reserved for separating whole numbers from their decimal or fractional parts, so we save it for later use.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 1: Lessons 1–10, Investigation 1

  1. Lesson 1

    Lesson 1: Review of Addition

  2. Lesson 2

    Lesson 2: Missing Addends

  3. Lesson 3

    Lesson 3: Sequences

  4. Lesson 4

    Lesson 4: Place Value, Activity Comparing Money Amounts

  5. Lesson 5

    Lesson 5: Ordinal Numbers, Months of the Year

  6. Lesson 6

    Lesson 6: Review of Subtraction

  7. Lesson 7Current

    Lesson 7: Writing Numbers Through 999

  8. Lesson 8

    Lesson 8: Adding Money

  9. Lesson 9

    Lesson 9: Adding with Regrouping

  10. Lesson 10

    Lesson 10: Even and Odd Numbers

  11. Lesson 11

    Lesson 11: Investigation 1 Number Lines, Activity Drawing Number Lines