In mathematics, "one more" and "one less" refer to the concept of adding or subtracting 1 from a given number.

When we add 1 to a number, we get the number that comes right after it. For example:

- If we have the number 5 and we add 1, we get 6.
- If we have the number 10 and we add 1, we get 11.

So, adding 1 to a number gives us the next number in the sequence.

On the other hand, when we subtract 1 from a number, we get the number that comes right before it. For example:

- If we have the number 8 and we subtract 1, we get 7.
- If we have the number 15 and we subtract 1, we get 14.

So, subtracting 1 from a number gives us the previous number in the sequence.

Let's look at some examples:

- If we start with the number 9, one more than 9 is 10, and one less than 9 is 8.
- If we start with the number 20, one more than 20 is 21, and one less than 20 is 19.

Understanding "one more" and "one less" helps us develop number sense and grasp the concept of number sequences.

.Study GuideOne More, One Less Worksheet/Answer key

One More, One Less Worksheet/Answer key

One More, One Less Worksheet/Answer key

One More, One Less Vocabulary/Answer keyOne More, One Less

Number and Operations (NCTM)

Understand numbers, ways of representing numbers, relationships among numbers, and number systems.

Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.

Connect number words and numerals to the quantities they represent, using various physical models and representations.

Compute fluently and make reasonable estimates.

Develop and use strategies for whole-number computations, with a focus on addition and subtraction.

Develop fluency with basic number combinations for addition and subtraction.

Algebra (NCTM)

Use mathematical models to represent and understand quantitative relationships.

Model situations that involve the addition and subtraction of whole numbers, using objects, pictures, and symbols.

Grade 2 Curriculum Focal Points (NCTM)

Number and Operations and Algebra: Developing quick recall of addition facts and related subtraction facts and fluency with multi-digit addition and subtraction

Children use their understanding of addition to develop quick recall of basic addition facts and related subtraction facts. They solve arithmetic problems by applying their understanding of models of addition and subtraction (such as combining or separating sets or using number lines), relationships and properties of number (such as place value), and properties of addition (commutativity and associativity). Children develop, discuss, and use efficient, accurate, and generalizable methods to add and subtract multi-digit whole numbers. They select and apply appropriate methods to estimate sums and differences or calculate them mentally, depending on the context and numbers involved. They develop fluency with efficient procedures, including standard algorithms, for adding and subtracting whole numbers, understand why the procedures work (on the basis of place value and properties of operations), and use them to solve problems.