← Atlas of Difficulties
S-04
The child confuses 14 and 40, 15 and 50 — numbers that sound alike
What the research says
Among the symptoms of dyscalculia are naming numbers incorrectly and a weak command of math vocabulary. Speech disorders and underdeveloped phonemic perception make learning to count considerably harder.
Lalaeva R.I. Dyscalculia in Children, pp. 23–25 (2005)
Exercises at home — free
Fingers don't lie
Builds: Telling the teens apart from the round tens through physical reinforcement
You need: just your hands
- Explain the rule: tens are shown on the left hand, ones on the right.
- Say a number: “Forty.”
- The child shows 4 fingers on the left hand (4 tens) and 0 on the right.
- Say: “Fourteen.”
- The child shows 1 finger on the left hand (1 ten) and 4 on the right.
- Mix up the numbers: 16, 60, 13, 30, 17, 70.
- Harder: the child names the number from the adult's fingers.
Lalaeva R.I. Dyscalculia in Children, 2005, ch. 3
Without help
- Mistakes when writing numbers from dictation
- Confusion when solving problems with numbers from 11 to 20