1. Magdalena practices mathematics by first multiplying a number by 2, then adding 16 to the product. She multiplies the resulting sum by 2 again, adds 16, and continues this process... From which single-digit natural number did she start calculating if at one point the result was 68?
1. The number 68 Magdalena could have obtained after adding 16 to the previous result.

The initial number is calculated backward, by subtracting the number 16 and then dividing by 2.

$1 \text{ POINT}$

$68-16=52$

$52: 2=26$

$26-16=10$

$10: 2=5$

The sought initial number is 5.

2 POINTS

The number 68 Magdalena could have obtained after multiplying the previous result by 2.

The initial number is calculated backward, by dividing by 2 and then subtracting the number $16. \quad 1$ POINT

$68: 2=34$

$34-16=18$

$18: 2=9$

The sought initial number is 9.

2 POINTS

Magdalena could have started calculating from the number 5 or from the number 9.

Note: A correct solution without the procedure or explanation should be graded with ONE POINT.

TOTAL 6 POINTS