Compatible numbers
- Addition. This includes all numbers that end in those pairs of numbers as well. ...
- Subtraction. Like in addition, numbers that end in 0 are compatible numbers because we can largely ignore the 0s, perform the subtraction, then attach the appropriate number of 0s after.
- Multiplication and division. Compatible numbers for multiplication and division are very similar. Like with addition and subtraction, numbers that end in one or more 0s are typically compatible.
- Compatible numbers and estimation. Compatible numbers are often used to estimate values by converting actual values that we want to do arithmetic with to compatible numbers.
How do you estimate compatible numbers?
Your Personal Years, Months, and Days
- Personal day number
- Personal month number
- Personal year number
- The influence of personal day, month, and year cycles (a wonderful planning aid)
How do you show your work of compatible numbers?
Some discussion questions you can ask your students include:
- Do the two numbers add together to make the tidy sum?
- How did you choose the pairs of numbers?
- How did you work that out?
- What was your strategy?
- Why did you use that strategy?
How do you use rounding and compatible numbers?
How do you estimate a sum?
- To estimate an amount to the tenth we have 3 steps to follow:
- STEP 2: We add the rounded numbers.
- STEP 1: Round the summands.
- STEP 2: Add the rounded numbers.
- STEP 3: Look at the total amount of rounding.
- We have rounded the two summands down.
How do you estimate quotient using compatible numbers?
Compatible numbers are numbers that are close to the numbers they're replacing that divide evenly into each other. The quotient is the result you get when you divide. 56,000 is pretty close to 55,304. 800 is pretty close to 875, AND it divides evenly into 56,000. Divide the non-zero parts of each number, 56 ÷ 8, to get the first part of the ...
How do you solve using compatible numbers?
0:304:43Grade 4 Math 4.5, Estimate Quotients using Compatible NumbersYouTubeStart of suggested clipEnd of suggested clipIf we wanted to find out how many times it be in one minute what we would do is find a number closeMoreIf we wanted to find out how many times it be in one minute what we would do is find a number close to 220 that divides easily by three.
What is an example of a compatible number?
Compatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally. When using estimation to approximate a calculation, replace actual numbers with compatible numbers. The numbers 500 and 300 are compatible for addition, since the sum of 800 can be easily calculated mentally.
How do you add compatible numbers?
0:183:39Grade 3 Math #1.4, Compatible numbers and Mental math strategiesYouTubeStart of suggested clipEnd of suggested clipIf you needed to add these up instead of adding 2 plus 6. If you know that 2 plus 8 is. 10. Then youMoreIf you needed to add these up instead of adding 2 plus 6. If you know that 2 plus 8 is. 10. Then you can just do that. And six plus four is ten.
What are compatible numbers in multiplication?
0:062:01How Do I Multiply Using Compatible Numbers? - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe most compatible numbers are 2 and 10 so whenever you have to multiply by 5 I want you to think 2MoreThe most compatible numbers are 2 and 10 so whenever you have to multiply by 5 I want you to think 2 and 10. So if we say 60 6.
What is the compatible numbers for 99999 and why?
What is the compatible number for 99999 and why? If finding a compatible number to replace 99999 for estimation purposes, 100000 is the closest, easy to work with number.
How do you round compatible numbers?
4:005:003rd Grade Math Rounding and Compatible Numbers - YouTubeYouTubeStart of suggested clipEnd of suggested clipThink of numbers that end with 25 50 or 75 think of using those in quarters 125 will be fiveMoreThink of numbers that end with 25 50 or 75 think of using those in quarters 125 will be five quarters to be like a dollar 25 cents 75 cents will be like three quarters.
What are compatible pairs in addition?
What are compatible pairs in addition? Numbers that easily combine to equal benchmark numbers (Compatible numbers are those that, when combined, add up to numbers like 100. For example, 25 + 75 = 100, so 25 and 75 are a compatible pair.)
What are compatible numbers in fractions?
Compatible numbers are numbers that are close in value to the real number that would make it easier to find an estimate calculation. Here is a multiplication problem. You can find an estimate of the product by rounding the numbers to the nearest hundreds place. Compatible numbers for 395 and 103 are 400 and 100.
How can you use compatible numbers and rounding to estimate differences?
0:1714:563rd Grade Math 1.8, Estimate Differences - YouTubeYouTubeStart of suggested clipEnd of suggested clipNumber so they're easy to add in our head if we had to subtract 47 minus 24 we could use compatibleMoreNumber so they're easy to add in our head if we had to subtract 47 minus 24 we could use compatible numbers 47 is close to 50 24 is close to 25. We could do 50 minus 25 that would be 25..
What is compatible numbers 3rd grade?
Compatible numbers are numbers that are easy to work with mentally, such as parts of 10. Students who memorize 8 + 2 = 10 can more easily reason that 10 - 2 = 8. By third grade, students can also quickly answer 80 + 20 or 100 - 20 by recognizing compatible numbers.
What do you mean by compatibility?
Compatibility is the capacity for two systems to work together without having to be altered to do so. Compatible software applications use the same data formats. For example, if word processor applications are compatible, the user should be able to open their document files in either product.
Does 5.5 round up or down?
Here's the general rule for rounding: If the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is 40. If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
How do you round using compatible numbers?
Rounding with the purpose of estimating the value of calculations is the best use of compatible numbers. To do this, round each number in the prob...
What are some examples of compatible numbers?
Compatible numbers, numbers that are easy to work with mentally, differ depending on the operation. Addition: Numbers that end in zeros, or add to...
What is the difference between rounding numbers and compatible numbers?
Rounding is a process used to find compatible numbers. The rounding itself is not a compatibility construct; only when the number is rounded to a...
What is the compatible number for 99999 and why?
If finding a compatible number to replace 99999 for estimation purposes, 100000 is the closest, easy to work with number. However, if looking for...
What is a compatible number in fractions?
Compatible numbers in fractions, just like compatible numbers in general, are numbers that are easy to work with mentally. Sometimes it is necessa...
Why are compatible numbers used?
Compatible numbers. Compatible numbers are numbers that seem to "go together" because they are easy to compute mentally. For various reasons, it is easier to compute addition, subtraction, multiplication, and division problems mentally using compatible numbers than numbers that are not compatible. As such, compatible numbers are commonly used ...
What is compatible with multiplication?
Compatible numbers for multiplication and division are very similar. Like with addition and subtraction, numbers that end in one or more 0s are typically compatible. For multiplication, 0 multiplied by anything is 0, so zeros on the end of multiplication problems can be removed. For multiplication, any zeros ...
What is the rule for a number that ends in 0?
One general rule that applies to all the basic arithmetic operations is that numbers that end in 0 (or multiple 0s) are compatible numbers , since in most cases they are easier to work with.
Why are numbers that end in 0 compatible?
Like in addition, numbers that end in 0 are compatible numbers because we can largely ignore the 0s, perform the subtraction, then attach the appropriate number of 0s after. Numbers that end with the same final digit are therefore compatible, since subtracting any number by itself results in 0.
How much does Travis pick up candy?
Travis picks up 2 candy bars for $0.99 each , an apple for $1.69, a bag of chips for $1.39, and a sandwich for $4.88. Estimate how much Travis will have to pay for all of it together if there is a 10% sales tax.
Do you have to break up numbers to recognize them?
It is not actually necessary to break the numbers up if you recognize them, but when doing the mental math, recognizing these numbers is as if you are doing so. This is why such numbers are referred to as compatible numbers, since, with some practice, they become easily recognizable to us.
What are Compatible Numbers?
Mathematical operations are easy to calculate with a calculator. As long as a person understands the process for calculation and has a calculator, any numbers can be manipulated through any amount of mathematical operations with ease using a calculator.
Reasons to Use Compatible Numbers
Many calculations are difficult to conduct mentally, however, it is good to be able to do mental calculations.
Compatible Numbers: Examples
Compatible numbers differ by mathematical operation. There are sets of compatible numbers for each operation and major mathematical calculation like fractions and estimating.
Definition of a Compatible Number
When we think of the word, 'compatible,' we often think of two people that go quite well together, like the historical Shakespearian couple, Romeo and Juliet, or American outlaws, Bonnie and Clyde. We may also think of foods that taste great together, like peanut butter and jelly or hot dogs and ketchup.
Why Do We Use Compatible Numbers?
When we are asked to find the sum (in addition), difference (in subtraction), product (in multiplication), or quotient (in division), our heads can sometimes spin. We use compatible numbers to make the problem easier to solve in our head by rounding each number to the nearest ten, twenty, fifty or hundred.
Examples of Compatible Number Usage
Let's take a look at some examples of compatible number usage from each of the four common mathematical operations: addition, subtraction, multiplication, and division. To make things more fun, let's use examples from real life using money. Who doesn't love money?
Mental Maths – Compatible Numbers Strategy
I hope you’ve been enjoying my ideas for teaching mental maths. So far we’ve looked at the counting on strategy and near doubles strategy. Today we’re looking at the compatible…
What are compatible numbers?
Compatible numbers are numbers that when added produce a ‘tidy sum’, one that usually ends in zero, or multiples of 10. For example, 7 and 3; 6 and 4; 8 and 2; and 9 and 1 are considered compatible because when added they total 10 (end in zero).
Compatible numbers activity
For this activity you will need a whiteboard. On the whiteboard write a list of compatible numbers in random order within a frame. Below is an example of compatible numbers you could use that total 10 (for younger students) as well as some that total 100.
Addition
Subtraction
- Like in addition, numbers that end in 0 are compatible numbers because we can largely ignore the 0s, perform the subtraction, then attach the appropriate number of 0s after. Numbers that end with the same final digit are therefore compatible, since subtracting any number by itself results in 0.
Multiplication and Division
Compatible Numbers and Estimation