lesson
Keep track of what changes
1 · Learn
Read what each number represents. A two-step problem needs an intermediate result before the final answer.
A library starts with 2,450 books, receives 375 and lends out 628. Adding gives 2,825 books before lending. Then subtracting gives 2,197 remaining. Label the intermediate amount so you do not confuse it with the answer.
2 · Worked example
I check that the final number is below 2,450 because more books left than arrived. This is a reasonableness check, not a substitute for calculating.
3 · Your turn
A hall has 1,260 seats. On one visit, 485 adults and 397 children attend. How many seats are empty?
Check your answer
882 seats are occupied; 1,260 − 882 = 378 seats are empty.
4 · Apply your learning
Draw a bar to represent the whole hall and its occupied parts. Explain why adding all three numbers would answer the wrong question.
Adult guidance and safety
Use practical or drawn representations and explain the method. Check units and labels. A correct answer to one example is not evidence of secure fluency; revisit with varied numbers and feedback.
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