Compare the given problem statements in each row, without calculating. Circle the one that is more. Share your thinking in class.
373 + 23 or 373 + 40
373 + 40 is more because adding 40 is greater than adding 23 to the same number.
240 + 10 or 204 + 10
240 + 10 is more because 240 is greater than 204, and both add the same amount (10).
900 + 9 or 890 + 60
890 + 60 is more because 890 + 60 = 950, while 900 + 9 = 909.
345 – 45 or 345 – 54
345 – 45 is more because subtracting a smaller number (45) leaves more than subtracting a larger number (54).
800 – 8 or 700 – 8
800 – 8 is more because starting with 800 and subtracting 8 leaves more than starting with 700 and subtracting 8.
Explanation
(a) When adding to the same base number, the expression with the larger addend gives a larger result. (b) When adding the same amount to two different numbers, the larger starting number gives a larger result. (c) Even though 900 > 890, the addition of 60 vs 9 makes a significant difference. 950 > 909. (d) When subtracting from the same number, subtracting less gives a larger result. (e) When subtracting the same amount, the larger starting number gives a larger result.