Number Sense Math Methods

Students with good number sense can... think and reason flexibly with numbers use numbers to solve problems. spot unreasonable answers. understand how numbers can be taken apart and put together in different ways. see connections among the operations. figure mentally. make reasonable estimates. (Marilyn Burns)

Students with poor number sense... tend to rely on procedures rather than reason. do not notice when answers or estimates are unreasonable. have limited numerical common sense. (Marilyn Burns)

Teaching Strategies to Build Number Sense Model different methods for computing. Ask students regularly to calculate mentally. Have class discussions about strategies for computing. Make estimation an integral part of computing. Question students about how they reason numerically. Pose numerical problems that have more than on possible answer. (Marilyn Burns)

Activities to build Number Sense Ten Black Dots by Donald Crews Quick Images (Investigations) Dot Cards Dominos Grow and Shrink Snap Algebra Triangles

Literature Ten Black Dots by Donald Crews Math–ter-pieces by Greg Tang Anno’s Counting Book Each Orange Had 8 Slices How Many Snails

Model different ways for computing. Mentally double 38. Then analyze the method you used in order to arrive at the answer.

Ask students regularly to calculate mentally. The center region of a dartboard is worth 100 points; the next ring is worth 50 points, the next 25 points, and the outermost, 10 points. Betty throws six darts and earns a score of 150. Where might her darts have landed?

Have class discussions about strategies for computing. Who else solved this in a different way? Keep track of students’ ideas and strategies on the board or chart.

Make estimation an integral part of computing. How many times do you think a piece of yarn or string equal to your height would wraparound your head as a headband? Imagine a soft drink can. Suppose you take a piece of yarn and wrap it around the can to measure its circumference. Do you think the circumference is longer, shorter, or abut the same as the height of the can? How high to you think the circumference measure will reach?

Question students about how they reason numerically. Why do you think that? Explain why that makes sense? Tell more about how you reasoned?

Pose numerical problems that have more than one possible answer. How could I spend exactly $1.00 by buying two things with different prices? How could I spend exactly $1.00 by buying three things with different prices. How could I spend exactly $1.00 by buying three different things with different prices, if one of them cost $0.39.