Every addition has matching subtractions, and the other way round!
From plus to minus:
235,000 + 120,000 = 355,000, so 355,000 - 120,000 = 235,000 holds.
Always write the matching reverse task next to it.
The numbers written in show the answer.
Example
For parents
What does this exercise practice?
This exercise shows that plus and minus are inverse operations, with big numbers too. Anyone who understands that can check their work and find mistakes themselves.
Common pitfalls
Children often just reverse the operation signs but mix up the positions of the numbers. Saying it out loud helps: 355,000 minus 120,000 makes 235,000, so 235,000 plus 120,000 equals 355,000.
How to practice at home
Write down an addition with big numbers and find the two subtractions to go with it together. That way checking becomes a habit.
Related: Number Sentences with a Gap, Written Addition, Column subtraction