In mathematics, subtraction is the operation of removing objects from a set. The result is called the difference of the set. In elementary mathematics, subtraction is often taught as a part of addition. Subtraction is commutative, meaning that the order of the operands does not affect the result:

For example,

5 − 3 = 3 − 5

The inverse of subtraction is addition. That is,

x + (y − z) = (x + y) − z

for all x, y, and z.

A subtraction table is a simple grid-like table that helps children learn and practice the subtraction facts. The table has two columns and as many rows as the child needs. The first column is the starting number, and the second column is the result of subtracting the first number from the second number.

For example, the table below shows the results of subtracting 1 from 2, 2 from 3, 3 from 4, and so on.

1 2 3 4

−1 1 2 1

The first row of the table shows that subtracting 1 from 2 results in 1. The second row of the table shows that subtracting 2 from 3 results in 1. The third row of the table shows that subtracting 3 from 4 results in 1. And so on.

Children can use a subtraction table to help them learn and practice the subtraction facts. They can simply look up the facts in the table, or they can use the table to solve problems. For example, if they are given the problem 5 − 3, they can look up 5 − 3 in the table to find the answer, which is 2.

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## What are subtraction facts to 20?

What are subtraction facts to 20?

Subtraction facts are a set of basic facts that students learn in order to subtract numbers. The facts to 20 are:

– Subtracting zero from any number is the same as leaving the number the same.

– Subtracting a number from itself is the same as leaving the number the same.

– Subtracting a number from a number with a smaller value is the same as subtracting the smaller number from the larger number.

– Subtracting a number from a number with a larger value is the same as adding the smaller number to the larger number and then subtracting the original number from the result.

For example, if we want to subtract 5 from 10, we can do it in two steps:

1. Add 5 to 10 to get 15.

2. Subtract 15 from 10 to get 5.

## How do you teach subtraction to 20?

When teaching subtraction, it is important to start with the basics. In order to subtract 20 from a number, first you need to understand what 20 looks like. 20 is made up of two 10s, so in order to subtract it, you need to take away 10s.

To teach subtraction to 20, start by showing your students how to subtract 10s. Have them use manipulatives, such as ten pennies or ten blocks, to help them understand. Explain to them that when they subtract 10, they are taking away 10 of the total amount. Show them how to subtract 10 using an example, such as 10-5=5.

Next, show your students how to subtract 2s. Explain that when they subtract 2, they are taking away 2 of the total amount. Show them how to subtract 2 using an example, such as 2-1=1.

Finally, combine the skills of subtraction 10s and 2s to subtract 20 from a number. Explain that when they subtract 20, they are taking away 10 of the total amount and 2 of the total amount. Show them how to subtract 20 from a number using an example, such as 20-8=12.

## What are basic facts to 20?

What are basic facts to 20?

1. A human typically has 20 teeth in their mouth.

2. A human typically has 20 fingers and toes.

3. A human typically has 20 bones in their ears.

4. A human typically has 20 muscles in their tongue.

5. A human typically has 20 bones in their skull.

6. A human typically has 20 ribs.

7. A human typically has 20 vertebrae.

8. A human typically has 20 segments in their intestine.

9. A human typically has 20 gallons of blood.

10. A human typically has 20 atoms in their body.

## What is a subtraction fact?

A subtraction fact is a math fact that is used to solve subtraction problems. There are a number of subtraction facts that students need to know in order to be successful in math. Some of the most basic subtraction facts are the following:

-5 – 3 =

2

-8 – 4 =

-4

-9 – 6 =

-3

## What are subtraction facts to 10?

Subtraction facts to 10 are a set of basic math facts that students need to know in order to subtract two numbers correctly. These facts involve subtracting numbers within 10, and are usually learned in elementary school.

The basic subtraction facts to 10 are as follows:

-9 – 8 = -1

-7 – 6 = -1

-5 – 4 = -1

-3 – 2 = -1

-1 – 0 = -1

-10 – 9 = -1

-8 – 7 = -1

-6 – 5 = -1

-4 – 3 = -1

-2 – 1 = -1

0 – 1 = -1

## How do you teach subtraction facts?

The subtraction facts are the most basic facts in mathematics. They are the basic knowledge that a child needs to be able to subtract numbers. Just as addition facts are learned through repeated practice and memorization, subtraction facts can be learned in a similar way.

One way to help a child learn the subtraction facts is to use a number line. A number line can be drawn on a piece of paper, or it can be a visual representation on a computer or tablet. The number line can help the child see the relationships between the numbers. For example, if a child is trying to subtract 4 from 8, they can see that 4 is four spaces to the left of 8 on the number line. This will help them to understand that 4 is subtracted from 8 by moving 4 spaces to the right on the number line.

Another way to help a child learn the subtraction facts is to use flashcards. Flashcards can be made with paper or with a computer or tablet. The flashcards can have the numbers on them, or they can have the answers. The child can quiz themselves on the flashcards, or they can be used in a game with a friend or family member.

One more way to help a child learn the subtraction facts is to use worksheets. There are many different types of subtraction worksheets available online. The worksheets can be used to help the child practice the subtraction facts.

## How do you teach number facts to 20?

How do you teach number facts to 20?

One way to help students learn number facts is to use a variety of activities and games. For instance, flashcards can help students learn and memorize basic addition and subtraction facts. Additionally, students can practice solving math problems as a group by playing games such as “math war” or “math dominoes.” In these games, students race to solve math problems and then compare their answers. If two students have the same answer, they take turns flipping over a domino or card to see who has the next problem.

Another strategy for teaching number facts is to use a variety of number lines. For example, a number line can be used to help students understand addition and subtraction facts. In addition, number lines can be used to help students understand place value and to develop a better understanding of fractions and decimals.

Finally, teachers can also use manipulatives to help students learn number facts. For instance, teachers can use counting bears, geoboards, or Cuisenaire rods to help students visualize and understand basic math concepts.