Open Middle®
Directions: Use the digits 1 to 9, at most one time each, to create two numbers that have a product as close to 500,000 as possible. NOTE: You may use any length of factors as you would need. Ex 8 digit by 1 digit. 4 digit by 3 digit.
Hint
What can you estimate to get close to 500,000?
How many digits did you use?
How many digits did you use?
Answer
947 x 528= 500,016
Source: Miles Knight
One of my 5th grade students came up with this one:
731 x 684 = 500,004
She is very, very excited!!
Can we use decimals?
My student also got 500,004 by multiplying 684 by 713!
My student got 500,000!!!!
7812.5×64
No where does it say you can’t use decimals. He talked me through his thinking and it was brilliant. I was so excited and I’ve never seen him with a smile that big before.
I got 499993.6.
7812.4×64
My 5th grade students were excited to find these equations.
947 x 528 = 500016
731 x 684 = 500004
7812.5 x 64 = 500000
124,567 x 4=498268
512 x 976
167 245 x 3 = 501 735