In the middle sits the spider with its starting number.
Each leg calculates twice on the way out.
First starting number + first number = middle number.
Then middle number + second number = outer number.
Example:
5 + 3 = 8, then 8 + 4 = 12
Always keep working from the inside outwards.
Example
For parents
What does this exercise practice?
This task practices calculating in two steps. The result of the first calculation becomes the starting number of the second, an important step towards multi-step arithmetic.
Common pitfalls
Some children add both numbers of a leg to the middle number instead of working in two steps. Have them say the middle number out loud before moving on.
How to practice at home
Say a starting number and then two small numbers in turn. Whoever says the outer number first gets a point. Then turn it around and look for the middle number.
Related: Spider, Caterpillar