Open Middle®
Directions: Using the digits 0 to 9, at most one time each, place a digit in each box to create a true equation.
Hint
What two-digit numbers would be too low/high that when multiplied together would not make a three-digit product?
Answer
There are many possible true equations including 32 x 15 = 480 and 52 x 15 – 630.
Source: Robert Kaplinsky
These are the solutions my fifth graders in Wisconsin came up with:
59×12=708
26×35=910
27×34=918
Would 52×15 actually be a solution? My students noticed there was a 5 in each factor, which would be using two number twice. 🙂
I think your 6th graders are correct.
32 x 18 = 576
38 x 12 = 456
27 x 34 = 918
These are the 17 unique solutions:
12*38=456
12*39=468
12*48=576
18*32=576
16*37=592
13*46=598
12*57=684
13*56=728
18*42=756
14*59=826
27*34=918
12*78=936
18*52=936
14*67=938
14*68=952
13*74=962
18*54=972
(you can always swap the two factors to get another 17 solutions)
32 x 15 = 480
32×15=480
i came up with more(●’◡’●)
11×63=693
11×33=363
11×32=352
11×54=594
11×81=891
11×17=187
11×62=682
i did this in my head btw
my mom taught me a way to do 11s
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Donkey, IF YOU DONT GET OUT I WILL HAUNT YOU FOR YOUR WHOLE LIFE GET OUTTTT!!!!!!!!!!
I am a student and I got 47×28=316
I found 55 times 55 which is 3025
merp meep merp merpmeep merrrrrrrrrrrrpppp merp
98×10=980
Maths tutor with 10 year old student:
09×52=468
59×04=236
08×52=416
78×04=312
67×12=804
67×14=938