Curated OER
Choose the Operation: Plus or minus (up to 100)
Investigate the relationship between addition and subtraction as scholars fill in these number sentences, each of which is missing a symbol. Is it a subtraction or addition equation? There are 20 of these to start, all written...
DK Publishing
Choosing the Operation, part 2
Choose the symbol; mathematicians can get confused between division and multiplication, so drill these skills with them. They examine 54 number sentences without a symbol, writing either the multiplication or division operation into the...