Use the units method: sugar = 1 unit, flour = 4 units.<br><br>
[[model:questions/solutions/q7227.png]]<br><br>
&bull; 1 unit → 0.5 kg of sugar<br>
&bull; Flour = 4 units → 4 × 0.5 = 2.0 kg<br><br>
2.0 kg of flour is needed.<br>
Check: Sugar : Flour = 0.5 : 2.0 = 1 : 4. ✓