The Inchworm

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An inchworm is crawling along at a steady speed of $\frac {3}{8}$ of a foot per minute. How far will the inchworm crawl in $\frac {4}{5}$ of a minute?

(a): What multiplication problem is this, and why? Use groups and objects per group to explain.
(b): Solve the original problem using a picture. Use our meaning of fractions to explain what you drew and why you drew it.
(c): How can we see that the denominator is the product of the original denominators? Use the meaning of the denominator and the meaning of multiplication to explain. What is one group? One object?
(d): How can we see that the numerator is the product of the original numerators? Use the meaning of the numerator and the meaning of multiplication to explain. What is one group? One object?

Write your own multiplication story for $\frac {8}{5} \times \frac {2}{3}$ .

(a): Explain how you know your story is correct. What is one group? One object?
(b): Solve the original problem using a picture. Use our meaning of fractions to explain what you drew and why you drew it.
(c): How can we see that the denominator is the product of the original denominators? Use the meaning of the denominator and the meaning of multiplication to explain. What is one group? One object?
(d): How can we see that the numerator is the product of the original numerators? Use the meaning of the numerator and the meaning of multiplication to explain. What is one group? One object?

An inchworm crawled for $\frac {2}{7}$ of a minute before stopping to take a break. The inchworm is $\frac {5}{8}$ of an inch long. How many minutes will it take the inchworm to crawl twice its body length?

Explain why this is not a story problem for $\frac {2}{7} \times \frac {5}{8}$ .

2025-09-03 01:08:28