Adding and subtracting large numbers (4th grade math)
I show examples of how to add and subtract numbers with up to six digits, with regrouping (carrying/borrowing). We also add a few numbers with mental math, solve a word problem about a library, and solve a problem that Mathy my mammoth mascot made up... about the weights of the mammmoths in Mathy's family. :)
See also
Find all the factors of a given number — online practice
Math Mammoth Grade 4 curriculum