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Foundation: Number Sense

California Infant/Toddler Learning & Development Foundations.
The developing understanding of number and quantity
8 months 18 months 36 months

At around eight months of age, children usually focus on one object or person at a time, yet they may at times hold two objects, one in each hand.

At around 18 months of age, children demonstrate understanding that there are different amounts of things.

At around 36 months of age, children show some understanding that numbers represent how many and demonstrate understanding of words that identify how much. (By 36 mos.; American Academy of Pediatrics 2004, 308)

For example, the child may:

  • Hold one block in each hand, then drop one of them when the infant care teacher holds out a third block for the child to hold. (6.5–7.5 mos.; Parks 2004, 50)

  • Watch a ball as it rolls away after hitting it with her hand. (5.5–8 mos.; Parks 2004, 64)

  • Explore one toy at a time by shaking, banging, or squeezing it. (5.5–8 mos.; Parks 2004, 58; 8 mos.; Meisels and others 2003, 21; birth–8 mos.; Lally and others 1995, 78–79)

  • Notice when someone walks in the room.

For example, the child may:

  • Communicate “more” and point to a bowl of apple slices. (18 mos.; Meisels and others 2003, 37)

  • Shake head “no” when offered more pasta. (18 mos.; Meisels and others 2003, 37)

  • Make a big pile of trucks and a little pile of trucks.

  • Use hand motions or words to indicate “All gone” when finished eating. (12–19 mos.; Parks 2004, 122)

  • Put three cars in a row.

For example, the child may:

  • Pick out one object from a box or point to the picture with only one of something. (Scaled score of 10 for 35:16–36:15 mos.; Bayley 2006, 97; 24–30 mos.; Parks 2004)

  • Reach into bowl and take out two pieces of pear when the infant care teacher says, “Just take two.” (30–36 mos.; Parks 2004)

  • Start counting with one, sometimes pointing to the same item twice when counting, or using numbers out of order; for example, “one, two, three, five, eight.” (36 mos.; Engaging Young Children 2004, 178)

  • Use fingers to count a small number of items. (around 36 mos.; Coplan 1993, 3)

  • Look at a plate and quickly respond “two,” without having to count, when the infant care teacher asks how many pieces of cheese there are. (36 mos.; Engaging Young Children 2004, 178)

  • Hold up two fingers when asked, “Show me two” or “How old are you?” (36 mos.; Engaging Young Children 2004, 178; by 36 mos.; American Academy of Pediatrics 2004, 308)

  • Identify “more” with collections of up to four items, without needing to count them. (36 mos.; Engaging Young Children 2004, 31 and 180)

  • Use more specific words to communicate how many, such as a little or a lot. (Hulit and Howard 2006, 186)

Behaviors leading up to the foundation (4 to 7 months)

During this period, the child may:

  • Explore toys with hands and mouth. (3–6 mos.; Parks 2004, 10)

  • Reach for second toy but may not grasp it when already holding one toy in the other hand. (5–6.5 mos.; Parks 2004, 49; scaled score of 10 for 5:16–6:15 mos.; Bayley 2006, 55)

  • Transfer a toy from one hand to the other. (5.5–7 mos.; Parks 2004)

  • Reach for, grasp, and hold onto a toy with one hand when already holding a different toy in the other hand. (Scaled score of 10 for 6:16–7:15 mos.; Bayley 2006, 56)

  • Track visually the path of a moving object. (6–8 mos.; Parks 2004, 64)

Behaviors leading up to the foundation (9 to 17 months)

During this period, the child may:

  • Try to hold onto two toys with one hand while reaching for a third desired toy, even if not successful. (Scaled score of 9 for 10:16–11:15 mos.; Bayley 2006, 58; 8–10 mos.; Parks 2004, 50)

  • Hold a block in each hand and bang them together. (8.5–12 mos.; Parks 2004)

  • Put several pegs into a plastic container and then dump them into a pile. (12–13 mos.; Parks 2004, 65)

Behaviors leading up to the foundation (19 to 35 months)

During this period, the child may:

  • Get two cups from the cupboard when playing in the housekeeping area with a friend. (21 mos.; Mix, Huttenlocher, and Levine 2002)

  • Look at or point to the child with one piece of apple left on his napkin when the infant care teacher asks, “Who has just one piece of apple?” (24–30 mos.; Parks 2004, 74)

  • Give the infant care teacher one cracker from a pile of many when she asks for “one.” (25–30 mos.; Parks 2004; scaled score of 10 for 28:16–30:15 mos.; Bayley 2006, 73)

Next Foundation: Classification

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Questions:   Early Education Division | 916-322-6233
Last Reviewed: Tuesday, November 7, 2023
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