525 + 125 = 650
120+80
94
30+600+630
250 and 750, which sum to 1000. The exact sum is 1001.
You could use 250 and 750.
94
120+80
30+600+630
650 + 290 = 940
250 and 750, which sum to 1000. The exact sum is 1001.
You could use 250 and 750.
In general, numbers are not compatible or otherwise in isolation. They are compatible in the context of other numbers. Two (or more) numbers are compatible if their sum (or other combination) is a number which YOU find easy to work with. As you acquire more experience, you may find that more and more numbers become compatible.
88 is the sum of those two numbers.
17 and 4: sum is 21.
Compatible numbers are pairs of numbers that are easy to compute with mentally, typically because they are rounded or simplified to make arithmetic calculations easier. For example, 50 and 20 are compatible numbers for estimating the sum of 48 and 19, as they round neatly to 50 and 20, making it simple to calculate that their sum is approximately 70. This concept is often used in estimation to quickly assess the reasonableness of an answer.
Well, honey, if you wanna estimate the sum of 17 and 75, you could round them both to the nearest ten. So, 17 rounds up to 20 and 75 rounds down to 70. Add those together and you get a rough estimate of 90. But hey, who needs estimates when you can just do the math and get the exact sum of 92?
you can use whole numbers