问题
填空题
497+498+499+500+501+502+503=______×______.
答案
497+498+499+500+501+502+503,
=(500-3)+(500-2)+(500-1)+500+(500+1)+(500+2)+(500+3),
=500×7+(3+2+1-1-2-3),
=500×7,
=3500;
故答案为:500,7.
497+498+499+500+501+502+503=______×______.
497+498+499+500+501+502+503,
=(500-3)+(500-2)+(500-1)+500+(500+1)+(500+2)+(500+3),
=500×7+(3+2+1-1-2-3),
=500×7,
=3500;
故答案为:500,7.