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  Number and Math Play

The Bottom Line
 
Q Look carefully at each line of numbers in the number pyramid. What number should replace the question mark in the middle of the bottom line? Explain why.

        8
2 5 2
1 2 4 2 1
1 2 1 3 1 2 1
1 2 1 1 ? 1 1 2 1

 
 
A The number 2 should replace the question mark. Each horizontal row adds up to one more than the one above it, so the last row must add up to 12.

STRATEGY: Look for a pattern