Common Core Standards: Mathematical Concepts Your Child Should Learn in Grade 1
In Grade 1, for Common Core Standards, students expand their skills with numbers and incorporate the use of more numbers and details when solving math problems and looking at shapes. Common Core Standards for Grade 1 emphasize four areas:

Addition and subtraction of whole numbers: Students develop a more sophisticated understanding of addition and subtraction as they grasp the concepts of add to, take from, put together, and take apart. They may also use comparison subtraction, in which they determine how many more objects are in one group than another. They also acquire strategies for solving addition and subtraction problems more quickly and easily.

Whole number relationships and place value: Working primarily with numbers from 1 to 100, students begin to recognize numbers in terms of tens and ones and use this understanding to solve addition and subtraction problems more easily.

Length measurements: Students develop an understanding of how to measure in units and how to indirectly compare the measurement of two objects by comparing each object to a third object. Practicing comparing the measurements of multiple objects (especially when the objects aren’t similar) helps your child transfer his understanding of measurements to a wider range of objects that he’ll see in everyday life.

Composing and decomposing two and threedimensional shapes: Students combine and separate two and threedimensional shapes and compare shapes in preparation for understanding properties such as congruence and symmetry.
Operations and algebraic thinking
Addition and subtraction using the numbers 1 to 20 are the primary focus. Students use counting to add on or take away numbers in addition and subtraction problems and practice determining whether equations are true or false.
With a set of concrete objects, give your child groups of objects (such as five spoons and four forks) to add together. In this example, she would count up to nine utensils. Then ask her to write the equation for the problem she just solved — for example, 5 + 4 = 9.
Number and operations in base ten
Students count to 120 and dig deeper into the concept of place value. Students demonstrate that any number in the tens place represents a certain number of tens.
For example, 30 is 3 sets of 10, 80 is 8 sets of 10, and so on. The symbols > (greater than), < (less than), and = (equal to) are used to compare twodigit numbers, and students begin to add and subtract with one and twodigit numbers within 100.
Continue practicing with place value. Compare the value of numbers using the tens place by using the symbols >, <, and = with numbers from 10 to 90. Challenge your child to explain why numbers are smaller or larger than others by referencing the value of numbers in the tens place.
Measurement and data
The use of measuring continues, including ordering multiple objects by their length and using the length of other objects to indirectly measure and order an object. Students discover how to tell and write time using digital and analog clocks, and they begin to use basic data, such as the number of forks and spoons in your kitchen, to compare and contrast different categories.
Have your child rearrange objects in your home by length — shortest to longest or vice versa. Reinforce your child’s ability to communicate the correct time of day by telling and writing time at various periods during the morning, afternoon, and evening.
Geometry
In Grade 1, students are expected to recognize attributes of shapes and which attributes define certain shapes, such as that a rectangle has four sides, that a circle is round, and so on. Students combine shapes in two and three dimensions to create other shapes and divide shapes into parts. They also become familiar with the concepts and terms half, fourth, and quarter.
Incorporate learning into meal times by having your child practice using the terms half, fourth, and quarter during food preparation. You can also incorporate these skills into playtime with any object that can be separated or divided.