Lunisolar Calendar

A lunisolar calendar is a calendar system that is based on both the cycles of the moon (lunar) and the position of the sun (solar). This type of calendar is used in many traditional cultures and is often associated with religious or cultural events.

The lunar part of the calendar is based on the phases of the moon, with each month corresponding to a complete lunar cycle, which is about 29.5 days. The solar part of the calendar is based on the position of the sun, with adjustments made to keep the calendar aligned with the seasons.

One of the most well-known lunisolar calendars is the Hebrew calendar, which is used to determine the dates of Jewish religious observances. Another example is the traditional Chinese calendar, which is used for determining festivals and holidays in China and other East Asian countries.

Lunisolar calendars often require the addition of extra months or days to keep the calendar synchronized with the solar year. This is known as intercalation.

◂Math Worksheets and Study Guides Third Grade. Double Digit Subtraction

Study Guide

Double Digit Subtraction

Worksheet/Answer key

Double Digit Subtraction

Worksheet/Answer key

Double Digit Subtraction

Worksheet/Answer key

Double Digit Subtraction

Worksheet/Answer key

Double-Digit Subtraction

The resources above cover the following skills:

Number and Operations (NCTM)

Compute fluently and make reasonable estimates.

Develop fluency in adding, subtracting, multiplying, and dividing whole numbers.

Select appropriate methods and tools for computing with whole numbers from among mental computation, estimation, calculators, and paper and pencil according to the context and nature of the computation and use the selected method or tools.

Algebra (NCTM)

Use mathematical models to represent and understand quantitative relationships.

Model problem situations with objects and use representations such as graphs, tables, and equations to draw conclusions.

Connections to the Grade 3 Focal Points (NCTM)

Number and Operations: Building on their work in grade 2, students extend their understanding of place value to numbers up to 10,000 in various contexts. Students also apply this understanding to the task of representing numbers in different equivalent forms (e.g., expanded notation). They develop their understanding of numbers by building their facility with mental computation (addition and subtraction in special cases, such as 2,500 + 6,000 and 9,000 - 5,000), by using computational estimation, and by performing paper-and-pencil computations.