🇹🇭 อ่านบทนี้เป็นภาษาไทย — จำนวนเต็ม (ชั้นมัธยมศึกษาปีที่ 1)
Chapter 1
Integers, Squares and Roots
Integers, Squares and Roots
Numbers below zero, the four operations on them, and the squares and square roots that every later chapter leans on — the foundation the rest of Stage 7 is built from.
- หลักสูตรแกนกลาง / สสวท.
- จำนวนและพีชคณิต (Number and Algebra)ตรงกับ ม.1 บทที่ 1 จำนวนเต็ม และบทที่ 3 เลขยกกำลัง
- Common Core (US)
- 6.NS, 7.NS, 8.EE
- Cambridge
- Lower Secondary Stage 7 — Number: integers, powers and roots
1.1 Negative numbers and the number line
Counting numbers are enough for counting things. They are not enough for a bank balance of baht, or for a temperature degrees below zero. Integers fill in the half of the number line that was missing.
นิยาม
Integer
A whole number with no fraction or decimal part: . It can be positive, negative, or zero.
- Three kinds of integer
- Positive integers — , to the right of zero
- Zero — neither positive nor negative; it is the reference point
- Negative integers — , to the left of zero
- Ordering, and the trap in it
- Further right on the number line always means greater
- , because sits to the right of
- Owing 2 baht is better than owing 7 baht — the same fact in words
ข้อควรระวัง
The most common mistake in this chapter: reading as larger than because . With a minus sign in front, the bigger the digit, the smaller the number.
นิยาม
Absolute value
The distance from a number to zero, written with two vertical bars: and . It is never negative, because a distance cannot be.
| English | ภาษาไทย |
|---|---|
| integer | จำนวนเต็ม |
| positive / negative | จำนวนบวก / จำนวนลบ |
| number line | เส้นจำนวน |
| absolute value | ค่าสัมบูรณ์ |
| greater than / less than | มากกว่า / น้อยกว่า |
📖 3 more sections of this chapter are being checked
The whole chapter is written; we read it back section by section before releasing it, because maths nobody has checked should not be on a public page. What is open is complete — nothing here is abridged.
Read it — now practise it
Generate a worksheet on this topic, or sit a timed mock paper.