- 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.
- Example 1 (Addition) 500 + 300 = 800.
- Example 2 (Subtraction) 19.4 − 3.8 = 15.6.
- Example 3 (Multiplication)
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)
What is the difference between compatible numbers and rounding?
- 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.
- Example 1 (Addition) 500 + 300 = 800.
- Example 2 (Subtraction) 19.4 − 3.8 = 15.6.
- Example 3 (Multiplication)
How to use compatible numbers to find two estimates?
Summary
- 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 estimate
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.
What are compatible numbers examples?
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.Example 1 (Addition) 500 + 300 = 800. ... Example 2 (Subtraction) 19.4 − 3.8 = 15.6. ... Example 3 (Multiplication)
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.
How do you use compatible numbers in math?
In mathematics, compatible numbers are the numbers that are easy to add, subtract, multiply, or divide mentally. Compatible numbers are close in value to the actual numbers that make estimating the answer and computing problems easier.
How do you teach compatible numbers?
0:273:39Grade 3 Math #1.4, Compatible numbers and Mental math strategiesYouTubeStart of suggested clipEnd of suggested clipAnd six plus four is ten. So instead of adding two and then adding six and then adding eight andMoreAnd six plus four is ten. So instead of adding two and then adding six and then adding eight and then adding four if you can see the compatible. Numbers you can say in your head.
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.
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.
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..
How do you use rounding or compatible numbers to estimate the sum?
2:027:06Estimate Sums Using Rounding and Compatible Numbers | Grade 3YouTubeStart of suggested clipEnd of suggested clip10 then i will round the second addend to the nearest. Ten then the estimate sum will be the sum ofMore10 then i will round the second addend to the nearest. Ten then the estimate sum will be the sum of the two rounded numbers to round to the nearest ten i will circle the tenth digit.
How do you use compatible numbers in division?
0:485:09Compatible Numbers in Division - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo there should be a zero on either my quotient or my divisor. So it would be three times 90 equalsMoreSo there should be a zero on either my quotient or my divisor. So it would be three times 90 equals 270 so that we could both compatible.
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...
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
- Examples of compatible numbers in addition include: 1. 1 and 9 2. 2 and 8 3. 3 and 7 4. 4 and 6 5. 5 and 5 This includes all numbers that end in those pairs of numbers as well. This is because adding those specific numbers results in a number than ends in 0, which allows us to easily compute the addition mentally. We can also fairly easily add numbers that end in 5 and 0. If ther…
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 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 at the end of the pairs of numbers can be ignored to simplify the proble…
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. Shopping is an activity in which we may use compatible numbers to get a rough estimate of how much we are going to spend before actually bringing our items to the register. Estimating in this manner works for ro...