Revise multiplying by 11 by multiplying the number by 10 and then adding the number to the answer. Sounds confusing? Try it out.
Multiply by 12 by multiplying by 10, multiplying by 2 and adding the 2 answers. Use the 'Help' link to explain further.
Multiply by 21 by multiplying the number by 20 and then adding the number to the answer.
To multiply a number by 19, multiply it by 20 and then subtract 19.
Partition a 2-digit number to make it easier to multiply by a single digit.
Just 60 seconds to answer as many as possible. If you are lucky lots of multiplying by 10 will come up!
Find the ice creams and answer the questions before the bomb hits you! remember to hit the return key to complete each answer. Try to use as few moves as possible!