Problems for Week 10

1.  Last night I added together two numbers, each with two digits. I got an answer of 67 but I cannot remember what the numbers were. What could be some possibilities?


2.  What might the missing numbers be? There are 6 possibilities.

         ?? ÷ ? = 3 
 
3.  How could you calculate 23 x 4 if the 4 button on your calculator is broken?   


4.  What could you add to 361 to make it divisible by 10? How many solutions can you find? Can you make a rule for this?



5.  Using only your head work out what the missing numbers might be: 2? - 3? = ?0