Lesson 2: Math is Exploring and Thinking5.NF.B.4

I can…

I can make sense of a problem, plan a strategy, and use fractions of a whole number to compare quantities.

Key words

• quantity — A number with a meaning, like 540 meters.
• relationship — How two amounts are linked.
• strategy — A plan for how to solve a problem.
• reasonable — An answer that makes sense.
• persevere — Keep going when a problem is hard.

Steps

1. A bowl is full of peas — far too many to count one at a time. About how many peas are in the bowl?
2. I do not count every pea — I look for a group I CAN count, like one small cluster of about 10.
3. Then I ask how many of those clusters would cover the whole bowl. I count about 12.
4. 12 clusters of about 10 is 12 × 10 = 120, so my estimate is about 120 peas — a reasoned answer, close enough to be useful.

Try it

Diego is figuring out how much paint he needs for a fence. His first plan isn't working. Which approach best matches the idea that math is exploring and thinking?

Check your answer

Figure out what he knows and what he needs, make a plan, check how it's going, and try a new plan when he's stuck

Exploring and thinking is a cycle: make sense of the problem, make a plan, check your progress, and change your plan when you hit a dead end.

Sentence starter

I know ___ because ___.

Goal: I can explain my plan using the words we know, we don't know, and my strategy is ___ .