Grade 3Math
Big Numbers (Ten Thousands and More)Places, reading, and size of numbers bigger than ten thousand
Numbers bigger than ten thousand have the ten-thousands place, the hundred-thousands place, the millions place, and the ten-millions place. Let's see how to read big numbers by splitting them into groups of 4 digits from the ones place (the Japanese way), how to show their size with a number line and inequality signs, and how numbers change when you multiply them by 10 or divide them by 10.
The narration and the pictures are in Japanese. You can hear the same words that are used in class at a Japanese school.
- Video
- 3:15（10 scenes）
- Problems
- 3 problems
Open this lesson in Japanese（大きい 数（万の位））
- 1Numbers bigger than ten thousand0:00
- 2The ten-thousands place0:15
- 3The hundred-thousands, millions, and ten-millions places0:33
- 4Split into groups of 4 digits to read0:55
- 5Writing in numerals1:12
- 6How many thousands?1:32
- 7Number line1:48
- 8Comparing size2:09
- 910, 100, and 1000 times, and dividing by 102:35
- 10Let's try2:57
Let's try
Write the math sentence in your notebook first, then open the answer.
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1Write "seven hundred six man, nine hundred" in numerals. (Man means ten thousand.)
Hint
Think of it as the man group and the ones group (4 digits). Write 0 in the places with no number.
Answer
It is 7060900. The man group is seven hundred six and the ones group is nine hundred, so write 706 and 0900 side by side.
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2Which is bigger, 60900 or 69000? Write it with an inequality sign.
Hint
Compare in order from the biggest place. With an inequality sign, write the bigger number on the open side.
Answer
69000 > 60900. The ten-thousands place is the same, and the thousands place is 0 and 9, so 69000 is bigger.
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3What is 47 times 100? And what is 470 divided by 10?
Hint
Multiply by 10, and each digit moves up one place. Divide by 10, and each digit moves down one place.
Answer
If you multiply 47 by 100, each digit moves up two places, and it is 4700. If you divide 470 by 10, each digit moves down one place, and it is 47.
Words in this lesson
- ten-thousands place 一万の位
- The place one to the left of the thousands place. It shows how many ten-thousands there are.
- ten-millions place 千万の位
- The place one to the left of the millions place. 10 ten-millions put together is called a hundred million (ichi-oku).
- number line 数直線
- A straight line with marks on it that shows numbers. The farther right you go, the bigger the numbers.
- inequality signs 不等号
- The signs > and < that show which number is bigger. The open side is the bigger number.
For parents and guardians
- The names of lessons and the order of topics differ slightly between textbooks. This page follows the content of Japan's national curriculum guidelines (the Course of Study). Numbers up to 10000 are covered in the 2nd grade unit "Numbers up to 10000," and the system of oku (hundred millions) and cho (trillions) in the 4th grade unit "Big Numbers (Oku and Cho)."
- In Japanese, big numbers are easier to read when split every 4 digits from the ones place (unlike English, which groups digits in threes). Try drawing dividing lines in big numbers you find in flyers or the news, and then reading them aloud. Children often forget to write the 0 in empty places, so practicing writing down a number after reading it is also effective.
- The idea that multiplying by 10 moves each digit up 1 place and dividing by 10 moves it down 1 place connects to decimals and to oku and cho in 4th grade. Division as a calculation itself is learned in the next unit, "Division."