What is Inside a Teen? — 13 is Ten and Three (Double Ten-Frame)

Read-aloud excerpt from Anno's Math Games II — pages showing visual decompositions. 'Today we look at numbers BIGGER than 10. Like 12, 13, 14. What is INSIDE them?'

• Show MG-6 anchor chart for the first time
• Point to 13 on the chart: 'Thirteen has a hidden TEN. Let's find it.'

We have been working with numbers up to 10. Today we go bigger — 11, 12, 13, 14, all the way to 19. These are called TEEN numbers. And here is the AMAZING THING: every teen number is just TEN PLUS SOME ONES. Watch. I want to show 13. (Build on double ten-frame.) First I fill the first ten-frame completely — that's 10. (Place 10 yellow counters in the first frame.) Now I count out 3 more — those are the 'ones' — and place them in the second frame. (Place 3 red counters.) 10 plus 3 equals 13. (Write equation 10 + 3 = 13.) Read with me: 'Thirteen is one ten and three ones.' Let me show 14. (Build: 10 yellow + 4 red.) Fourteen = 10 + 4. One ten and four ones. Let me show 19. (Build: 10 + 9.) Nineteen = 10 + 9. One ten and nine ones.

• Twelve is one ten and two ones.

  model 10 yellow + 2 red = 12. 12 = 10 + 2.

  prompt Build 12 on the double ten-frame
• Seventeen is one ten and seven ones.

  model 10 + 7 = 17.

  prompt Build 17 on the double ten-frame
• Fifteen is one ten and five ones. The 10-train is the TEN. The 5 reds are the ONES.

  model 10 + 5 = 15.

  prompt Linking cubes: build a 10-train (white) + 5 extras (red)

• I show you 16 on the double ten-frame. How many in the first frame? (10.) How many in the second? (6.) So 16 is one ten and how many ones? (6.)
• If I want to build 18, I need a full ten-frame and how many more? (8.)

MG-6 Chart Physical / non-image

Teen Number place-value anchor chart: 24-inch poster showing each of 11-19 as a filled-ten-frame plus an extras-frame; 13 is shown as ten dots (full top frame) + 3 dots (in a partial bottom frame), with the decomposition 13 = 10 + 3 written below. Color: ten-frame dots in blue, extras dots in red. Mounted at child-height; used in lessons 9-10.

M-K-S-NS-09-A Chart

Large 24-inch poster. Header: 'TEEN NUMBERS = ONE TEN + SOME ONES'. Nine rows for 11 through 19. Each row shows: (1) the numeral in large 36-pt font, (2) a double ten-frame with first frame fully filled (10 blue dots) and second frame partially filled (1 to 9 red dots), (3) the equation '11 = 10 + 1' through '19 = 10 + 9'. Style: clean grid, blue tens / red ones, white background.

M-K-S-NS-09-B Video Physical / non-image

Top-down camera on a laminated double-ten-frame mat. Five builds in sequence. Build 11: hand fills first frame with 10 yellow counters, then places 1 red in second frame. Counter overlay '11 = 10 + 1'. Build 13: same first frame + 3 red. Counter '13 = 10 + 3'. And so on for 15, 17, 19. Voiceover: 'Eleven is one ten and one one. Thirteen is one ten and three ones. Fifteen is one ten and five ones. Seventeen is one ten and seven ones. Nineteen is one ten and nine ones.' Music: gentle xylophone.

• Build-the-Teen station: teacher calls a teen number (e.g., '14!'); children build it on their double ten-frame and state '14 is one ten and four ones.' Continue through 11-19.

  scaffold Pre-filled first ten-frame on the mat for children needing reduced load.
• Teen Decomposition Card Sort: children match teen-number cards (11, 12, ..., 19) with double-ten-frame picture cards and with equation cards (10+1, 10+2, ..., 10+9).

  scaffold Provide color-matched edges on related cards for self-checking.

• Build 15 on your double ten-frame. Write the equation 15 = 10 + ___.
• Say the sentence: '15 is one ten and ___ ones.'

• Math Detective close: 'TEEN numbers have a HIDDEN TEN. Tomorrow we practice more — and we count by tens to 100 to see WHY ten is so special.'

• Find a teen number at home (look at a calendar, a clock, a page number). Tell a grown-up: '___ is one ten and ___ ones.' Draw the double ten-frame for it.