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Singapore Math 5A · Independent learning

Numbers to One Billion

Learning target: Represent, read, compare, and decompose numbers through one billion; use digit values accurately.

Begin with the exact prerequisite checkpoint below. Afterward, explain why your strategy works, not merely which procedure to use.

Opening task

Explore · place value

Write 803,060,004 in expanded form, including its nonzero place values.

Show answer and worked explanation

Answer: 8 × 100,000,000 + 3 × 1,000,000 + 6 × 10,000 + 4

How it works: 8 is in the hundred-millions place, 3 in millions, 6 in ten-thousands, and 4 in ones.

Prerequisite check (before instruction)

Attempt without help. A weak prerequisite signals review of 4A or 4B material, not a failed 5A lesson.

Write the value of the 7 in 47,082.

Show answer and worked explanation

Answer: 7,000

How it works: The 7 occupies the thousands place, so 7 × 1,000 = 7,000.

How many hundreds make 5,000?

Show answer and worked explanation

Answer: 50 hundreds

How it works: 5,000 ÷ 100 = 50.

Lesson-specific prerequisite checkpoint

Do this without a worked example. If you cannot explain it, review the earlier skill before continuing.

In 40,306, what is the value of the 3?

Show answer and worked explanation

Answer: 300

How it works: The 3 is in hundreds; do not confuse its digit with its value.

Understand the idea

Represent, read, compare, and decompose numbers through one billion; use digit values accurately.

One billion is 1,000,000,000 (one followed by nine zeros). A digit has a face value (0–9) and a position. Build numbers by multiplying each nonzero digit by its place value. Zeros hold empty places so 305 million is not 35 million. Compare numbers from the greatest place left to right, and check each number on a scaled number line.

Vocabulary focus: place-value positions, inverse scaling, round-number factors. Make a small labeled model, work through the arithmetic, and explain the result in words.

Watch for: Confusing digit position with digit value or losing place-holding zeros.

Model to study: Nine-/ten-position place-value chart and scaled number line.

Worked examples

Worked examples 1 · place value

In 405,050,001, what is the value of the digit 5 in the millions place?

Solution: 5,000,000

Why: The digit 5 is in the millions place, so 5 × 1,000,000 = 5,000,000.

Worked examples 2 · compare

Which is larger, 302,070,004 or 302,770,004, and by how much?

Solution: 302,770,004; by 700,000

Why: Compare corresponding place values from left to right; subtract 302,770,004 − 302,070,004 = 700,000.

Worked examples 3 · place value

Write 502,090,001 in expanded form, including its nonzero place values.

Solution: 5 × 100,000,000 + 2 × 1,000,000 + 9 × 10,000 + 1

Why: 5 is in the hundred-millions place, 2 in millions, 9 in ten-thousands, and 1 in ones.

Check understanding

Check understanding 1 · place value

In 401,090,003, what is the value of the digit 1 in the millions place?

Show answer and worked explanation

Answer: 1,000,000

How it works: The digit 1 is in the millions place, so 1 × 1,000,000 = 1,000,000.

Check understanding 2 · compare

Which is larger, 405,020,003 or 405,120,003, and by how much?

Show answer and worked explanation

Answer: 405,120,003; by 100,000

How it works: Compare corresponding place values from left to right; subtract 405,120,003 − 405,020,003 = 100,000.

Guided practice

Guided practice 1 · place value

Write 603,020,001 in expanded form, including its nonzero place values.

Show answer and worked explanation

Answer: 6 × 100,000,000 + 3 × 1,000,000 + 2 × 10,000 + 1

How it works: 6 is in the hundred-millions place, 3 in millions, 2 in ten-thousands, and 1 in ones.

Guided practice 2 · place value

In 704,080,002, what is the value of the digit 4 in the millions place?

Show answer and worked explanation

Answer: 4,000,000

How it works: The digit 4 is in the millions place, so 4 × 1,000,000 = 4,000,000.

Guided practice 3 · compare

Which is larger, 404,090,006 or 404,290,006, and by how much?

Show answer and worked explanation

Answer: 404,290,006; by 200,000

How it works: Compare corresponding place values from left to right; subtract 404,290,006 − 404,090,006 = 200,000.

Independent practice

Independent practice 1 · place value

Write 706,040,008 in expanded form, including its nonzero place values.

Show answer and worked explanation

Answer: 7 × 100,000,000 + 6 × 1,000,000 + 4 × 10,000 + 8

How it works: 7 is in the hundred-millions place, 6 in millions, 4 in ten-thousands, and 8 in ones.

Independent practice 2 · place value

In 303,050,009, what is the value of the digit 3 in the millions place?

Show answer and worked explanation

Answer: 3,000,000

How it works: The digit 3 is in the millions place, so 3 × 1,000,000 = 3,000,000.

Independent practice 3 · compare

Which is larger, 606,020,004 or 606,120,004, and by how much?

Show answer and worked explanation

Answer: 606,120,004; by 100,000

How it works: Compare corresponding place values from left to right; subtract 606,120,004 − 606,020,004 = 100,000.

Independent practice 4 · place value

Write 905,040,003 in expanded form, including its nonzero place values.

Show answer and worked explanation

Answer: 9 × 100,000,000 + 5 × 1,000,000 + 4 × 10,000 + 3

How it works: 9 is in the hundred-millions place, 5 in millions, 4 in ten-thousands, and 3 in ones.

Independent practice 5 · place value

In 904,080,003, what is the value of the digit 4 in the millions place?

Show answer and worked explanation

Answer: 4,000,000

How it works: The digit 4 is in the millions place, so 4 × 1,000,000 = 4,000,000.

Challenge and error analysis

Challenge and error analysis 1 · worked-error diagnosis

Error-analysis notebook: Learner notebook (LESSON): “706,060,007 has zeros that do not matter, so I rewrite the number as 7,667.” Identify exactly which written step or assumption fails, correct it, and independently solve this new task: In 706,060,007, what is the value of the digit 6 in the millions place?

Show answer and worked explanation

Answer: 6,000,000

How it works: Wrong step/assumption: Learner notebook (LESSON): “706,060,007 has zeros that do not matter, so I rewrite the number as 7,667.” Diagnosis: Those zeroes hold place positions. Keep each three-digit period aligned; the resulting number is much smaller. Correct computation: The digit 6 is in the millions place, so 6 × 1,000,000 = 6,000,000.

Challenge and error analysis 2 · reasoning transfer

Reasoning and transfer: Solve, then explain a different way to check your answer (inverse operation, estimate, model, or units as appropriate). Which is larger, 301,050,008 or 301,450,008, and by how much?

Show answer and worked explanation

Answer: 301,450,008; by 400,000

How it works: Compare corresponding place values from left to right; subtract 301,450,008 − 301,050,008 = 400,000. Verification: show why the answer has a reasonable magnitude and matches the operation, referent and unit.

Targeted mastery: model, calculate, explain

These additional original examples address specific 5A mastery requirements. Compare the visual and the reasoning before trying the independent questions.

Targeted 1 · targeted mastery: name

Write 1,000,000,000 in words and name its highest place.

Solution: one billion; billions place

Why: A 1 in the billions place has value 1,000,000,000. The nine zeroes hold all smaller places.

Targeted 2 · targeted mastery: name

Write 405,030,006 in words. Explain the zero placeholders in all three place-value periods.

Solution: four hundred five million thirty thousand six

Why: In words: four hundred five million thirty thousand six. Separate into three-digit periods: 405 | 030 | 006. The 405 million period is four hundred five million: the 0 holds the ten-millions place. The 030 thousands period means 0 hundred-thousands, 3 ten-thousands and 0 thousands. The 006 ones period means 0 hundreds, 0 tens and 6 ones. These five zeros preserve the correct positions even though they are not spoken individually.

Targeted 3 · targeted mastery: name

Write “seven hundred two million eight thousand forty” in digits.

Show answer and worked explanation

Answer: 702,008,040

How it works: The millions, thousands and ones periods are 702 | 008 | 040. Combine them as 702,008,040.

Targeted 4 · targeted mastery: name

Which number is one billion: 100,000,000 or 1,000,000,000? Explain.

Show answer and worked explanation

Answer: 1,000,000,000

How it works: A billion is one thousand millions; 100,000,000 is one hundred million.

Exit check

Exit check 1 · compare

Which is larger, 909,080,001 or 909,780,001, and by how much?

Show answer and worked explanation

Answer: 909,780,001; by 700,000

How it works: Compare corresponding place values from left to right; subtract 909,780,001 − 909,080,001 = 700,000.

Exit check 2 · place value

Write 204,090,002 in expanded form, including its nonzero place values.

Show answer and worked explanation

Answer: 2 × 100,000,000 + 4 × 1,000,000 + 9 × 10,000 + 2

How it works: 2 is in the hundred-millions place, 4 in millions, 9 in ten-thousands, and 2 in ones.

Target for independent mastery: all exit-check problems correct plus a justified explanation. A tutor may reteach the concept if calculations are correct without meaningful reasoning.