A 4th/5th grade teacher I am working with planned to introduce division of fractions and needed some ideas. I knew that a context would really help kids make sense of the operation so I nudged her towards the book Minilessons for Operations with Fractions, Decimals and Percents (Imm, Fosnot & Uttenbogaard, 2008). We found a good place to start and I offered to lead the first string.
After we discussed the word ratio, I set up a ratio table with # of cans of paint and portion (of wall painted).
Continue reading “Division of fractions — The role of ratio”
My name is Jennifer DiBrienza. I taught elementary school in New York City public schools for 9 years and began using number strings then. When I moved to California, I completed my PhD in elementary mathematics education and now I teach at Stanford University and consult with school districts and education companies.
Last week I worked in a 2nd/3rd grade classroom. The students had started the school year with data collection, graphing and sorting, so they had done very little computation at about 5 weeks into the school year. The classroom teacher and I decided we’d build a subtraction number string to introduce the second graders to strings and to revisit them with the third graders.
Continue reading “Subtraction string – where is the answer?”