Prime numbers are all the rage these days. I can tell something’s up when random people start asking me about the randomness of primes—without even knowing that I’m a mathematician! In the past couple ...

When you subtract using large numbers, it's often better to use a written method. Column subtraction is a good written method to take one number away from another. It involves writing the smaller ...

Decompose numbers to subtract. Engage in a Number Talk focused on subtraction strategies. Decompose numbers to subtract. Engage in a Number Talk focused on subtraction strategies. Can you solve the ...