using a calculator find the numbers between 1 and 20 only using the numbers 1 & 7 and using x - = ( )
I'll get you started. 20 = 7 + 7 + 7 – 1
19 = 7 + 7 + 7 – 1 – 1
18 = 7 + 7 + 7 – 1 – 1 – 1
17 = 7 + 7 + 1 + 1 + 1
16 = 7 + 7 + 1 + 1
You can keep it going.
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