Math Investigations

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Chapter 16

Part 1: Home and School Investigation

Send the Letter to Family (PDF file) home with each child. Once all the children have brought in a paper with a description of a special day, organize the papers in numerical order. Each day, announce whose special day it is and why, making sure to focus on the number part of the date. For example, focus on the number 23 if it is May 23. When there are school holidays or weekends, be sure to announce those special days right before or right after. A good time to do this activity is after Lesson 4 on using the numbers on a calendar. This activity will work best if you send the letter home on the 20th of the month or earlier.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 5 on counting by twos, fives, and tens.


  • student worksheet for each group of two children
  • 30 counters for each group of two students

Introducing the Investigation

Tell the children that you are going to give them a bag of counters. Have them count the counters, first by twos and then by fives. Show them the student worksheet they can use to record their counting.

Doing the Investigation

When students are finished counting by twos and fives, you might also want to ask them to count by ones. Ask them if they got the same end number no matter which way they counted.

Houghton Mifflin Math Grade K