Ten Times as Many

10 min

Narrative

The purpose of this Choral Count is for students to practice counting by 12, 15, and 24, and to notice patterns in the count after 10 multiples. This understanding will help students later in this lesson when they represent quantities that are 10 times as many, using tape diagrams. 

When they use the words “multiple,” “value,” and “place,” students use language precisely (MP6).

Launch

  • “Count by 12 starting at 12.”
  • Record as students count.
  • Stop counting and recording after the tenth multiple has been said.
  • Repeat these steps, with 15 and 24.
Teacher Instructions
  • Circle the tenth multiple in from each count.
  • “What do you notice about the tenth multiple?” (It has a zero in the ones place.)
  • “Why do you think this is?” (The value is now 10 times as much as the first value.)
  • “Can you predict the twentieth multiple?”(It is the double of the tenth multiple and it also ends in zero.) 
  • 1–2 minutes: quiet think time
  • 1 minute: partner discussion
  • Share and record responses.

Sample Response

Sample responses:

  • Each tenth multiple ends with a zero.
  • The fifth multiple is half of the tenth multiple.
  • The twentieth multiple is twice the tenth multiple and also ends with zero.
Activity Synthesis (Teacher Notes)
  • “What would the tenth multiple be if we were counting by 192? 1092?” (1,920, 10,920)
Standards
Building Toward
  • 4.NBT.5·Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
  • 4.NBT.B.5·Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

20 min

15 min