Generate problems according to the grade, problem type, and quantity specified by the user; when no quantity is specified, generate 20 problems by default. By default, do not include answers; when the user requests checking, answers, or explanations, place the answers in a separate block after the problems to avoid seeing the answers during practice.
Currently supports first grade, second grade, and the 2026 new edition fourth grade first semester. When the user does not specify a grade, first determine it based on the problem type; when the same problem type spans grades or cannot be determined, ask for the grade.
First grade
- Addition within 100: two-digit plus two-digit, with the sum not exceeding 100, for example
12＋23＝。 - Subtraction within 100: the minuend is not less than the subtrahend, for example
23－12＝。 - Continuous addition, continuous subtraction, and mixed addition and subtraction: operations with three numbers, with all intermediate results kept between 0 and 100, for example
12＋23＋34＝、33－12－11＝、33＋12－11＝。 - Renminbi calculations: use only basic addition, subtraction, and conversion of yuan, jiao, and fen; both the problem statements and answers retain the units.
Second grade
- Vertical addition and subtraction within 100: create problems according to the difficulty of
33±12±11; when vertical form is needed, arrange the expressions in columns or clearly mark “calculate in vertical form.” - Multiplication within the table: multipliers are 1 to 9, for example
3×5＝。 - Multiplication with addition and multiplication with subtraction: combinations of multiplication and addition or subtraction with a one-digit number, for example
3×8±5＝; the result of subtraction must not be negative. - Division within the table: exact division problems, for example
24÷8＝。 - Mixed multiplication and division: use only multiplication and division within the table, with a clear order of operations and integer results.
- Division with remainders: divisors are 2 to 9, and the remainder is strictly less than the divisor, for example
25÷8＝（ ）……（ ）。 - Three-digit addition and subtraction and continuous addition and subtraction: results and intermediate results are not negative and do not exceed three digits, for example
223±214、555±214±214。 - Length unit conversion: basic conversion and addition and subtraction of meters and centimeters, units must be retained and
1 米＝100 厘米。
Fourth grade first semester (2026 new edition)
The core of this volume is number sense for large numbers, integer multiplication, laws of operations, quantitative relationships, and multiplication estimation. Use the following problem types; they may be mixed or given separately according to user requirements:
- Multiplication by whole tens, whole hundreds, and whole thousands: one or both multipliers end with 0, for example
24×200=、120×40=。 - Patterns of change in products: given a known product, change the trailing 0s of one or both multipliers, for example “given
14×2=28，140×20=”。 - Split mental calculation for two-digit by two-digit multiplication: results should be suitable for splitting using the distributive law, for example
13×12、15×11、22×13、16×14。 - Making round numbers using the commutative and associative laws of addition: for example
48+75+52、136+29+64。 - Making round numbers using the commutative and associative laws of multiplication: focus on covering
25×4、125×8、50×2combinations, for example25×17×4。 - Distributive law of multiplication: forward, reverse, and subtraction distributive law are all acceptable, for example
(40+4)×25、36×7+64×7、125×(80-8)。 - Reading, writing, and filling in blanks for large numbers: composition of numbers, decimal place value, and approximate numbers expressed in “ten thousand” or “hundred million,” for example
130000 里面有（ ）个万、498000≈（ ）万。 - Quantitative relationships: unit price × quantity = total price, speed × time = distance, and simple meeting problems with easy numbers.
- Multiplication estimation: require an estimated range or the result after rounding, for example
21×26≈、114×21≈、308×19≈。
Problem generation constraints
- Problems should be solvable by mental calculation, and the numbers and expression lengths should be similar to the examples for that problem type; avoid lengthy operations that require written calculation.
- Problems on making round numbers and laws of operations must have a clear entry point for simplification, and ordinary calculation problems must not be disguised as simplification problems.
- Two-digit by two-digit multiplication problems should be naturally decomposable into whole tens and ones, avoiding difficulty beyond the mental calculation level of this volume.
- Estimation problems use
≈; if the problem asks to "estimate the range," clearly give a reasonable range or the approximation method used. - Provide complete units for quantitative relationship problems; for meeting problems, clearly state "at the same time, moving toward each other" or equivalent conditions to avoid ambiguity.
- Avoid repetition within the same batch of problems, and maintain a balanced mix of problem types in mixed practice, unless the user specifies weights.
Tablet mental arithmetic homework
When the user requests that problems be assigned to Trello or a homework tablet, use the format in this section; the multi-column layout of the print version does not apply.
- One problem per line, retaining the complete problem statement, units, and answer space, without answers, solutions, name fields, or worksheet titles. Do not use Markdown tables, and do not place multiple problems on the same line; the number of columns and font size are automatically adapted by the tablet.
- All problems for each day serve as one
arithmeticassignment. Hand it to thehomeworkskill for scheduling, and write it according to thetrelloskill'scyeam trello card create --type arithmetic --task <多行题目>; there is no separatecyeam arithmeticcommand. - Explanations such as estimated duration and execution order go in
--desc, and the problems go in--task. The CLI generates the type and content identifier; no PDF or attachment is needed. - If the user separately requests answers, deliver them separately; they must not be mixed into the problem content of the tablet homework.
Printable worksheet output specification
When the user requests a "practice sheet," "print version," or does not specify the presentation format, organize the content according to this specification so that it can be used directly as input for a subsequent PDF. Problem content and answers must be separated.
- The top of the page includes, in order,
北师大版口算练习, grade and problem type, and number of problems; the second line reserves姓名：______ 日期：______ 用时：______分钟 正确：______/____。 - Problems are numbered consecutively starting from
1.. Each problem retains an equals sign and enough space to write the answer, for example1. 3×5＝（ ）; division with a remainder uses two spaces:25÷8＝（ ）……（ ）。 - Ordinary short arithmetic expressions use a monospaced multi-column grid: 5 columns by default; longer word problems, large-number problems, or three-digit chained calculations change to 3 columns; quantitative relationship problems change to 2 columns. If the number of problems is insufficient to fill the last row, leave the remaining spaces blank and do not renumber.
- Vertical addition and subtraction within 100 use vertical expressions in the problem area, with a horizontal line left for writing the answer; other problem types remain in horizontal mental-arithmetic form. Do not reveal answers, hint at steps, or show solutions in the problem area.
- When the user explicitly requests answers, start a separate "Answers" page or independent block and give concise answers with the same numbering; provide solutions only when the user explicitly requests them. The print version does not include answers by default.
- For text delivery, present it with a title, metadata, and numbered problems; when a PDF is needed, hand the same structure to the PDF skill to render as an A4 portrait practice sheet. The worksheet should not claim on its own that a PDF has already been generated or printed.
Example (short arithmetic problem area):
北师大版口算练习
二年级｜表内乘法｜20 题
姓名：______ 日期：______ 用时：______分钟 正确：______/____
1. 3×5＝（ ） 2. 7×8＝（ ） 3. 6×9＝（ ）
4. 4×7＝（ ） 5. 9×2＝（ ） 6. 8×6＝（ ）
Exclusions
The 2026 new edition of Grade 4 Volume 1 does not generate the old-version "multi-digit division mental arithmetic," especially three-digit divided by two-digit. In addition to the listed Grade 1, Grade 2, and Grade 4 content, content for Grade 3 and other semesters, fractions, decimals, and similar topics is not included in this skill for now; when the user raises them, explain the scope and wait for future expansion.