Nature Number Story - 3 Versions of a Separate with Unknown Result Problem
This week is our final installment of the number stories series. We started the series with two different joining problems with unknown results. Today completes the series with a second separating problem with an unknown result.
Why number stories?
Number stories are the key to helping your child build a connection between their counting skills and learning to add, subtract, multiply, and divide.
Contextual problems are the primary teaching tool to use to help children construct a rich understanding of the operations [addition, subtraction, multiplication, division]. These contexts are what elicit problem-solving strategies (Schwartz, 2013) and help children make sense of the operations. (Van de Walle, Teaching Student-Centered Mathematics, V1, pg 147)
Number stories allow our children to develop meaningful connections between their daily lives and their developing understanding of mathematics.
If the concept of number stories is new to you, I recommend first reading a bit more about number stories and why I start with joining and separating problems first in this post, Number Stories: Joining and Separating.
What type of problem are we solving today?
This week’s number story is a separating problem, which is different than the joining problems from the first two weeks. Separating problems are often called “take away” problems. Unlike joining problems, in which two quantities are joined together, separating problems begin with the whole (the largest quantity) and part is separated from it.
In this week’s problem, the result is unknown, which means we know how much we start with, we know how much we separate (take away), so we need to figure out how much remains at the end.
Why this problem type again?
Last week’s number story was a separating problem with an unknown result and this week’s is also. Why? It’s helpful for children to solve number stories in pairs because it allows them to apply their learning from the previous problem to the second problem. I don’t recommend directly telling a child that the problem type is the same as the one from the time before because removes an opportunity to build their critical thinking. However, the natural exposure to a repeated problem-type supports their ability to make sense of the problem.
This Week’s Problem
All the setup is done for you! Just grab some wildflowers (or something you can pretend is a set of wildflowers), sit down with your child, and show them the number story video.
There are three versions, so you can pick the one that’s the best fit for your child (same story, different numbers):
(1) Version 1: Numbers within 5 (Click button below for video): On a walk, you collect 5 wildflowers. When you pass your neighbor’s house, you share 2 wildflowers with your neighbor. How many wildflowers do you still have?
(2) Version 2: Numbers within 10 (Click button below for video): On a walk, you collect 8 wildflowers. When you pass your neighbor’s house, you share 3 wildflowers with your neighbor. How many wildflowers do you still have?
(3) Version 3: Numbers within 20 (Click button below for video): On a walk, you collect 16 wildflowers. When you pass your neighbor’s house, you share 6 wildflowers with your neighbor. How many wildflowers do you still have?
After the story, pause to give your child time to solve.
Once they solve it, the second half of the video shows one possible way to solve the story! Discuss similarities and differences between their strategy and mine. (REMEMBER there are LOTS of ways to solve! Flexible thinking is the goal.)
To see all the problems in this number stories series, visit the Number Stories page here.