Answer in Algebra for sneha bhardwaj #108991
Teaching all four models of subtraction–take-away, comparison, completion and whole/part/part–can better train elementary school children to think abstractly and relate their math knowledge for the real world.
For example, to teach children the take-away model, set a specific number (e.g. 10) of objects (apples, blocks, etc.) in front of them and ask them to take away a smaller number (e.g. 7) of objects. Then ask them how many objects remain.
For example, a completion subtraction is “7 + ? = 10.” Use the same blocks or apples you used in the take-away model to teach children this concept. Have them replace apples or blocks to the original set (e.g. 7) until they reach the desired number (e.g. 10).
An example of comparison subtraction is “If Chrissy is 26 and Bradley is 36, how many years older is Bradley than Chrissy?”.
The whole/part/part model of subtraction involves categories of objects that need to be subcategorized: “I have five apples for sale. Three are green apples. How many aren’t green apples?”.