Write down what is on each side of the scale
Skill, som
Builds on
- A letter can stand for a thing or for how much it weighs
- A measurement says how many, and of what
- The equal sign means both sides are the same amount
Leads to
- Adding nothing leaves a thing as it was
- Get the unknown by itself on the scale and read what it weighs
- Make any amount up to 15 from weights that double: 1, 2, 4, 8
- Putting two things together weighs the same in either order