Adding pairs of 3-digit numbers
1 We can complete the addition 465 + 123 using different methods. Why is 500 + 100 = 600 a useful estimate?
Adding place value parts 465 + 123 = 400 + 60 + 5 + 100 + 20 + 3 = 500 + 80 + 8 = 588
+ 100 + 20
+ 3
465
565 585588
Adding on 465 + 123 = 465 + 100 + 20 + 3 = 565 + 20 + 3 = 585 + 3 = 588
What is the same and what is different about the methods? Where can you see adding a multiple of 100?
2 What is different about the addition 469 + 123? Look at what happens when the 9 ones and 3 ones are added together.
4
6
9
5
9
2
469 + 123 = 400 + 60 + 9 + 100 + 20 + 3 = 500 + 80 + 12 = 592
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03/05/2022 10:20
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