Calculate 56 423 + 18 269 + 21 899 First estimate the answer by rounding off to the nearest 1 000. Look at the hundreds digit to round up or down: 56 423 rounds down to 56 000 because 4 is less than 5. 18 269 rounds down to 18 000 because 2 is less than 5. 21 899 rounds up to 22 000 because 8 is more than 5. The estimate is 56 000 + (18 000 + 22 000) = 56 000 + 40 000 = 96.000. To find the exact answer then using place values. (50 000+6 000+ 400+20 + 3) + (10,000+8000+ 200 +60 + 9) + (20 000 + 1 000 + 800 + 90 + 9) (50 000 + 10 000 + 20 000) + (6 000 + 8 000 + 1 000) + (400+ 200 + 800) + (20 +60 +90) + (3+9+9) 80 000 + 15 000 + 1 400 + 170 +21 = 95 000 + 1 000 + 500 + 70 +20 +1 96 000 + 500 + 90 +1​