Greek Primary Grade 2 / Mathematics / Αριθμοί και αξία θέσης

Αριθμοί έως το 1.000

Αριθμοί έως το 1.000: structured theory, worked examples, answered practice, and a mastery checklist for Greek Primary Grade 2.

学习目标

Recognise, explain, and apply “εκατοντάδες, δεκάδες και μονάδες”.
Recognise, explain, and apply “σύγκριση”.
Recognise, explain, and apply “στρογγυλοποίηση σε δεκάδες”.

核心概念与检查

I can convert safely between number forms.
I can explain why the chosen operation is appropriate.
Every solution or explanation for “Αριθμοί έως το 1.000” should include a method, justification, and final check.

单元

核心理论

练习前按清晰顺序掌握本章核心概念。

Represent before calculating

Write the number in a useful form, check sign and place value, and only then choose the operation. A clear representation reduces mechanical errors.

Equivalent forms

Fractions, decimals, percentages, ratios, and powers can describe the same quantity. Changing form is a solving tool, not a separate trick.

Reasonableness check

Estimate before and after the exact calculation. The sign, order of magnitude, and unit must agree with the problem context.

εκατοντάδες, δεκάδες και μονάδες

Use a suitable representation, state the rule, and keep every numerical or algebraic step equivalent. Finish with estimation, an inverse operation, or substitution as a check.

σύγκριση

Use a suitable representation, state the rule, and keep every numerical or algebraic step equivalent. Finish with estimation, an inverse operation, or substitution as a check.

στρογγυλοποίηση σε δεκάδες

Use a suitable representation, state the rule, and keep every numerical or algebraic step equivalent. Finish with estimation, an inverse operation, or substitution as a check.

Mathematics

例题讲解

逐步查看方法，并理解每一步为何成立。

Worked arithmetic example

4 equal groups contain 6 objects each. How many objects are there, and how can the answer be checked?

1Write repeated addition: 6 + 6 + 6 + 6.
2Connect it to 4 × 6.
3Check with division: 24 ÷ 4 = 6.

Thinking and explanation example

Explain “εκατοντάδες, δεκάδες και μονάδες” in your own words and use a picture, objects, a table, or a simple measurement to support it.

1State what is known and what is being found.
2Choose one clear representation.
3Explain what it shows and check that the answer is sensible.

A complete explanation connects the correct idea, a clear representation, and a sensible check.

Αριθμοί έως το 1.000

含答案练习

八道分层练习，从基础熟练到考试应用。请先独立完成，再查看提示或答案。

基础熟练3 分钟

Calculate 3 + 4 and show two representations connected with “εκατοντάδες, δεκάδες και μονάδες”.

提示

Use a number line, place value, or objects.

答案指南

3 + 4 = 7. Valid representations include number-line jumps and grouped objects.

基础熟练4 分钟

6 equal groups contain 6 objects each. Find the total and write an addition and multiplication statement.

提示

Add 6 a total of 6 times.

答案指南

6 + 6 + 6 + 6 + 6 + 6 = 6 · 6 = 36.

应用4 分钟

Continue 9, 12, 15, ... for three more terms and explain the rule.

提示

Check how much each term increases.

答案指南

18, 21, 24; +3.

应用5 分钟

A rectangle has sides 5 cm and 5 cm. Find its perimeter and explain why four sides are counted.

提示

Opposite sides are equal.

答案指南

Perimeter = 5 + 5 + 5 + 5 = 20 cm.

推理5 分钟

Out of 16 objects, 8 are shaded. What fraction is shaded and how does it simplify?

提示

Put shaded objects over the total.

答案指南

8/16 = 1/2.

推理6 分钟

The measurements are 4, 4, 4, and 4. Find the greatest, least, and range.

提示

Range = greatest value minus least value.

答案指南

Greatest 4, least 4, range 0.

考试题型7 分钟

Anna has 42 cards, gives away 7, then shares the rest into 5 equal groups. How many are in each group?

提示

Subtract first, then divide.

答案指南

42 - 7 = 35; (35) : 5 = 7.

考试题型8 分钟

A learner says 3 + 3 = 7. Find the error, correct it, and check the correction.

提示

Check with a number line or inverse subtraction.

答案指南

3 + 3 = 6; 6 - 3 = 3.

常见错误

Dropping brackets or using the wrong order of operations.
Converting a fraction or percentage without checking equivalence.
Answering without an estimate, unit, or sign check.

掌握度检查

I can convert safely between number forms.
I can explain why the chosen operation is appropriate.
I check the result with estimation or an inverse operation.

Αριθμοί έως το 1.000

章节作业

六道不同作业，从基础到挑战，包含预计用时、提示和答案指南。

基础5 分钟

Homework 1: Calculate 6 + 5 and show two representations connected with “εκατοντάδες, δεκάδες και μονάδες”.

提示

Use a number line, place value, or objects.

答案指南

6 + 5 = 11. Valid representations include number-line jumps and grouped objects.

基础6 分钟

Homework 2: 2 equal groups contain 9 objects each. Find the total and write an addition and multiplication statement.

提示

Add 9 a total of 2 times.

答案指南

9 + 9 = 2 · 9 = 18.

进阶7 分钟

Homework 3: Continue 5, 9, 13, ... for three more terms and explain the rule.

提示

Check how much each term increases.

答案指南

17, 21, 25; +4.

进阶8 分钟

Homework 4: A rectangle has sides 8 cm and 6 cm. Find its perimeter and explain why four sides are counted.

提示

Opposite sides are equal.

答案指南

Perimeter = 8 + 6 + 8 + 6 = 28 cm.

挑战10 分钟

Homework 5: Out of 12 objects, 4 are shaded. What fraction is shaded and how does it simplify?

提示

Put shaded objects over the total.

答案指南

4/12 = 1/3.

挑战12 分钟

Homework 6: The measurements are 7, 5, 7, and 5. Find the greatest, least, and range.

提示

Range = greatest value minus least value.

答案指南

Greatest 7, least 5, range 2.

35 分钟 / 30 分

完整章节测试

带计时器、完整分值和参考答案的章节自测。

Start the timer when ready, work without notes, show every step, and open model answers only after finishing.

1. Calculate 4 + 5 and show two representations connected with “εκατοντάδες, δεκάδες και μονάδες”.

2 分

答案指南

4 + 5 = 9. Valid representations include number-line jumps and grouped objects.

2. 2 equal groups contain 7 objects each. Find the total and write an addition and multiplication statement.

3 分

答案指南

7 + 7 = 2 · 7 = 14.

3. Continue 3, 7, 11, ... for three more terms and explain the rule.

3 分

答案指南

15, 19, 23; +4.

4. A rectangle has sides 6 cm and 6 cm. Find its perimeter and explain why four sides are counted.

4 分

答案指南

Perimeter = 6 + 6 + 6 + 6 = 24 cm.

5. Out of 27 objects, 9 are shaded. What fraction is shaded and how does it simplify?

4 分

答案指南

9/27 = 1/3.

6. The measurements are 5, 5, 5, and 5. Find the greatest, least, and range.

4 分

答案指南

Greatest 5, least 5, range 0.

7. Anna has 16 cards, gives away 8, then shares the rest into 1 equal groups. How many are in each group?

5 分

答案指南

16 - 8 = 8; (8) : 1 = 8.

8. A learner says 4 + 4 = 9. Find the error, correct it, and check the correction.

5 分

答案指南

4 + 4 = 8; 8 - 4 = 4.

单元

官方来源与核验

课程参考来源；教学顺序请始终与学校和老师确认。

Ινστιτούτο Εκπαιδευτικής Πολιτικής (ΙΕΠ)Official curriculum programmes and announcements.Ψηφιακό Σχολείο / Διαδραστικά Σχολικά ΒιβλίαOfficial school textbooks and available digital material.

Mathematics

Greek Primary Grade 2: 数学与物理的结构化路线，包含章节、练习和下一步。

返回科目

本章覆盖内容

结构跟随教材，用来帮助组织学习。

εκατοντάδες, δεκάδες και μονάδες

σύγκριση

στρογγυλοποίηση σε δεκάδες

重点关注

通常容易出错或需要更多复习的部分。

I can convert safely between number forms.

I can explain why the chosen operation is appropriate.

I check the result with estimation or an inverse operation.

来源、日常资料与学习资源

从教材、daily material、PDFs、videos 和 worked examples 开始。

Start from the official textbook or specification referenced on the subject page.

Use the notes and examples as support, not as a replacement for the official syllabus.

Check the current syllabus version before exam preparation.

按小主题练习

进入 full tests 前先做 targeted practice，让覆盖情况更清楚。