# Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context

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## Abstract

**:**

## 1. Introduction

#### 1.1. Challenges for Prevalence Studies

#### 1.2. Neurodevelopmental Models of Numerical Cognition

## 2. Materials and Methods

#### 2.1. Participants

#### 2.2. Screening and Domain-Specific Measures

#### 2.3. Procedures

#### 2.4. Data Analysis

^{2}; [73]), a adjusted and robust measure of fit for non-normal sample data, which is more accurate than the ordinary chi-square statistic [74]. To test the models’ fit, the following indices were considered: the ratio of chi-square to its degrees of freedom (SBχ

^{2}/df), the comparative fit index (CFI; [75]), the Tucker–Lewis Index (TLI; [76]), and the root mean square error of approximation (RMSEA; [77]). In the case of χ

^{2}/df, values below or equal to two are considered good, while values between two and three are considered acceptable [78]. For the TLI and CFI indices, values above 0.90 indicate acceptable fit, while values above 0.95 indicate excellent fit [79]. The RMSEA value is considered acceptable when it is below 0.08 and good when it is below 0.05 [80]. Furthermore, we used the Akaike Information Criterion (AIC; [81] and the Bayesian Information Criterion (BIC; [82]) to compare the different models and to choose the model that presented the lowest level of loss of information. Concerning the AIC and BIC indices, the model that minimizes those indices can be selected as the best model (see [83], for a discussion about AIC and BIC indices).

^{2}, which is sensitive to sample size, but also ΔCFI, which has been found to be the most sensitive index to detect a lack of invariance [84], employing the absolute value of ΔCFI of less than 0.01 [64,85].

## 3. Results

#### 3.1. Prevalence Criteria

#### 3.2. Dimensionality

^{2}/df = 2.2; CF = 0.97; TLI= 0.96; RMSEA = 0.06; AIC= 140.543; BIC= 244.620), Figure 2. Then the higher-order mathematical cognition solution (i.e., the four factors plus a mathematics cognition quotient (MC)) were tested by confirmatory factor analysis (CFA). Results showed that goodness of fit indices for the higher-order mathematical cognition solution were all adequate (SBχ

^{2}/df = 2.2; CFI= 0.97; TLI= 0.96; RMSEA= 0.06; AIC= 139.215; BIC= 235.858), Figure 3. Finally, the Dehaene’s triple code structure (Analogical Magnitude, Verbal code and Visual Arabic) was tested. Results showed the goodness of fit of the model (SBχ

^{2}/df = 1.7; CFI= 0.98; TLI= 0.97; RMSEA= 0.05; AIC= 143.440; BIC= 243.800), Figure 4.

#### 3.3. Gender Invariance

^{2}/df = 2.33; CFI = 0.94; TLI = 0.91; RMSEA = 0.08) and for girls (χ

^{2}/df = 1.43; CFI = 0.98; TLI = 0.96; RMSEA = 0.06).

^{2}= 1476.79, df = 90, p < 0.001). As reported in Table 2, in addition to configural invariance, the first-order factor loadings were equal across genders. Then, scalar, or strict invariance, which constrained intercepts to be invariant across groups, and, subsequently, the equivalence of the second-order factor loadings, was supported. Finally, after having tested those structural variances and covariances were invariant across gender, the equality of the items’ variances and covariances was confirmed. We also detected a lack of invariance employing the absolute value of ΔCFI that was less than 0.01 by the more restrictive model.

#### 3.4. Gender Differences

_{p}

^{2}= 0.05. Furthermore, Memory for Digits, Zareki-R Total, and Score A were analysed as dependent variables through separated ANCOVAs, with gender as the independent variable and age as a covariate. Outcomes revealed no significant main effects of gender for Memory for Digits; (F (1301) = 0.005; p = 0.94; η

_{p}

^{2}< 0.001) and for Zareki-R Total (F (1301) = 3.61, p = 0.06; η

_{p}

^{2}= 0.01). However, there was a borderline significant effect of gender on Score A (F (1301) = 4.03; p = 0.05; η

_{p}

^{2}= 0.01), with boys performing better than girls.

_{p}

^{2}= 0.18. Moreover, Tukey post hoc tests were used with a significant alpha level of P ≤ 0.05. Results are presented in Table 3.

#### 3.5. Reliability

#### 3.6. Criterion-Related Validity

## 4. Discussion

## 5. Conclusions

## Supplementary Materials

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## Appendix A

**Table A1.**Range of raw score results for Zareki-R subtests and total, number of students for each per Z-score, and classification by age groups.

Age 7 N = 36 | Age 8 N = 81 | Age 9 N = 75 | Age 10 N = 51 | Age 11 N = 28 | Age 12 N = 33 | Z-Score | Category | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Counting dots | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

34 | 2.0–4.0 | 78 | 2.0–4.00 | 65 | 2.0–4.00 | 45 | 3.0–4.00 | 25 | 3.0–4.00 | 31 | 3.0–4.00 | −1.49–+1.49 | Expected | |

2 | ≤1.0 | 3 | ≤1.0 | 10 | ≤2.0 | 6 | ≤2.0 | 3 | ≤2.0 | 2 | ≤2.0 | ≤−1.5 | Low | |

Counting Backwards | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

36 | 0–4.0 | 73 | 1.0–4.0 | 63 | 1.0–4.0 | 50 | 2.0–4.0 | 26 | 2.0–4.0 | 30 | 2.0–4.0 | −1.49–+1.49 | Expected | |

-- | NA | 8 | 0 | 12 | 0 | 1 | ≤1.0 | 2 | ≤1.0 | 3 | ≤1.0 | ≤−1.5 | Low | |

Dictation of Numbers | 2 | ≥13.0 | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

32 | 1–12.0 | 73 | 7.0–16.0 | 67 | 8.0–16.0 | 51 | 14.0–16.0 | 25 | 13.0–16.0 | 32 | 13.0 –16.0 | −1.49–+1.49 | Expected | |

2 | 0 | 8 | ≤6.0 | 8 | ≤7.0 | -- | ≤13.0 | 3 | ≤12.0 | 1 | ≤12.0 | ≤−1.5 | Low | |

Mental Calculation | 2 | ≥27 | 1 | ≥40 | -- | NA | -- | NA | -- | NA | -- | 44 | ≥1.5 | High |

34 | 0–26.0 | 74 | 9.0–39 | 69 | 14.0–44.0 | 51 | 25.0–44.0 | 26 | 21.0–44.0 | 30 | 20.0–43.0 | −1.49–+1.49 | Expected | |

-- | NA | 6 | ≤8.0 | 6 | ≤13.0 | -- | ≤24.0 | 2 | ≤20.0 | 3 | ≤19.0 | ≤−1.5 | Low | |

Reading Numbers | 2 | 16 | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

33 | 1.0–15.0 | 74 | 9.0–16.0 | 67 | 10.0–16.0 | 51 | 15.0–16.0 | 27 | 15.0–16.0 | 31 | 14.0–16.0 | −1.49–+1.49 | Expected | |

1 | 0 | 7 | ≤8.0 | 8 | ≤9.0 | -- | ≤14.0 | 1 | ≤14.0 | 2 | ≤13.0 | ≤−1.5 | Low | |

Positioning Numbers | 1 | ≥21.0 | 5 | 24.0 | -- | NA | -- | 24.0 | -- | NA | 2 | ≥23.0 | ≥1.5 | High |

32 | 2.0–20.0 | 68 | 9.0–23.0 | 68 | 9.0–24.0 | 50 | 14.0–23.0 | 25 | 12.0–24.0 | 29 | 13.0–22.0 | −1.49–+1.49 | Expected | |

3 | ≤1.0 | 8 | ≤8.0 | 7 | ≤8.0 | 1 | ≤13.0 | 3 | ≤11.0 | 2 | ≤12.0 | ≤−1.5 | Low | |

Oral Comparison | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

35 | 6.0–16.0 | 77 | 8.0–16.0 | 70 | 12.0–16.0 | 50 | 12.0–16.0 | 26 | 13.0–16.0 | 29 | 13.0–16.0 | −1.49–+1.49 | Expected | |

1 | ≤5.0 | 4 | ≤7.0 | 5 | ≤11.0 | 1 | ≤11.0 | 2 | ≤12.0 | 4 | ≤12.0 | ≤−1.5 | Low | |

Perceptual Estimation | 1 | 10 | 10 | 10 | -- | NA | -- | NA | 1 | 10 | -- | NA | ≥1.5 | High |

34 | 2.0–9.0 | 65 | 3.0–9.0 | 69 | 3.0–10.0 | 48 | 4.0–10.0 | 24 | 4.0–9.0 | 32 | 4.0–10.0 | −1.49–+1.49 | Expected | |

1 | ≤1.0 | 6 | ≤2.0 | 6 | ≤2.0 | 3 | ≤3.0 | 3 | ≤3.0 | 1 | ≤3.0 | ≤−1.5 | Low | |

Contextual Estimation | 1 | ≥15.0 | 6 | ≥18.0 | 4 | 20.0 | 6 | 20.0 | -- | NA | -- | NA | ≥1.5 | High |

35 | 2.0–14 | 75 | 3.0 –17.0 | 70 | 4.0–19.0 | 45 | 7.0–19.0 | 25 | 8.0–20.0 | 31 | 11.0–20.0 | −1.49–+1.49 | Expected | |

-- | ≤1.0 | -- | ≤2.0 | 1 | ≤3.0 | 0 | ≤6.0 | 3 | ≤7.0 | 2 | ≤10.0 | ≤−1.5 | Low | |

Problem Solving | 4 | ≥9.0 | 3 | ≥12.0 | -- | NA | -- | 14 | 3 | 14.0 | 1 | 14 | ≥1.5 | High |

32 | 0–8.0 | 78 | 0–11.0 | 70 | 2.0 –14.0 | 51 | 5.0–13.0 | 23 | 5.0–13.0 | 30 | 6.0–13.0 | −1.49–+1.49 | Expected | |

-- | NA | -- | NA | 5 | ≤1.0 | -- | ≤4.0 | 2 | ≤4.0 | 2 | ≤5.0 | ≤−1.5 | Low | |

Written Comparison | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | -- | NA | ≥1.5 | High |

34 | 12.0–20.0 | 75 | 15.0–20.0 | 68 | 17.0–20.0 | 49 | 17.0–20.0 | 22 | 18.0–20.0 | 31 | 17.0–20.0 | −1.49–+1.49 | Expected | |

2 | ≤11.0 | 6 | ≤14.0 | 7 | ≤16.0 | 2 | ≤16.0 | 6 | ≤17.0 | 2 | ≤16.0 | ≤−1.5 | Low | |

Zareki-R Total | 2 | ≥127.0 | 2 | ≥164.0 | 0 | ≥181.0 | 0 | ≥178.0 | 0 | ≥180.0 | 1 | ≥177.0 | ≥1.5 | High |

33 | 48.0–126.0 | 74 | 87.0–163 | 66 | 100.0–180.0 | 48 | 135.0–177.0 | 26 | 132.0–179.0 | 30 | 130.0–176.0 | −1.49–+1.49 | Expected | |

1 | ≤47.0 | 5 | ≤86.0 | 9 | ≤99.0 | 3 | ≤134.0 | 2 | ≤131.0 | 2 | ≤129.0 | ≤−1.5 | Low |

**Table A2.**Individual row scores on Zareki-R of children diagnosed with DD on the 5th percentile and/or on z-scores.

Classification | p/z | p/z | p/z | p/z | p/z | Z | p/z | p/z | p/z | p/z | z | z | z | z | z | p/z | p/z | p/z | p/z | z | p/z | Z |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Age | 7 | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 10 | 10 | 10 | 11 | 11 | 12 | 12 |

Gender | F | M | M | M | M | M | F | M | M | M | F | M | F | F | F | F | F | F | F | M | M | F |

Counting dots | 1 | 4 | 1 | 4 | 3 ^{†} | 3 ^{†} | 3 | 4 | 2 ^{†} | 3 | 4 | 1 | 4 | 4 | 2 ^{†} | 3 ^{†} | 4 | 4 | 4 ^{†} | 4 ^{†} | 4 ^{†} | 4 ^{†} |

Counting backwards | 0 ^{†} | 0 | 0 | 2 | 1 ^{†} | 3 | 1 ^{†} | 0 | 1 ^{†} | 0 | 3 | 2 | 2 | 0 | 1 ^{†} | 1 | 4 | 3 ^{†} | 4 | 3 ^{†} | 1 | 3 ^{†} |

Dictation of numbers | 4 ^{†} | 6 | 0 | 2 | 5 | 10 ^{†} | 4 | 8 ^{†} | 4 | 6 | 4 | 15 | 4 | 4 | 5 | 14 ^{†} | 16 | 10 | 14 ^{†} | 16 | 10 | 13 ^{†} |

Mental calculation | 2 ^{†} | 10 ^{†} | 0 | 2 | 0 | 2 | 0 | 4 | 15 ^{†} | 4 | 26 | 13 | 6 | 24 | 12 | 16 | 20 | 20 | 6 | 18 | 13 | 16 |

Reading numbers | 2 ^{†} | 4 | 2 | 12 | 4 | 8 ^{†} | 5 | 8 | 12 | 6 | 12 | 10 ^{†} | 8 | 8 | 4 | 12 | 16 | 15 ^{†} | 14 | 16 ^{†} | 11 | 13 ^{†} |

Positioning numbers | 0 | 4 | 5 | 12 ^{†} | 15 | 12 ^{†} | 12 | 4 | 16 | 4 | 3 | 11 ^{†} | 16 | 4 | 20 | 10 | 19 ^{†} | 20 | 12 ^{†} | 17 | 13 ^{†} | 16 |

Memory of Digits | 26 ^{†} | 18 ^{†} | 12 | 18 ^{†} | 14 | 20 | 18 | 20 | 8 | 20 | 12 | 10 ^{†} | 14 | 16 | 18 | 18 ^{†} | 22 | 14 | 20 ^{†} | 16 | 16 | 16 |

Oral comparison | 6 ^{†} | 4 | 4 | 12 | 9 ^{†} | 10 | 10 | 16 | 8 | 12 ^{†} | 10 | 15 | 14 | 14 | 12 ^{†} | 12 ^{†} | 9 | 14 | 14 ^{†} | 14 ^{†} | 11 | 16 ^{†} |

Perceptual estimation | 0 | 2 | 6 ^{†} | 6 ^{†} | 8 | 0 | 2 | 6 | 4 ^{†} | 6 | 6 | 2 | 6 | 4 ^{†} | 4 ^{†} | 2 | 6 ^{†} | 4 | 6 ^{†} | 7 | 6 ^{†} | 10 |

Contextual estimation | 4 ^{†} | 16 ^{†} | 4 ^{†} | 6 ^{†} | 8 ^{†} | 10 ^{†} | 12 ^{†} | 10 ^{†} | 4 ^{†} | 8 ^{†} | 4 ^{†} | 4 ^{†} | 8 ^{†} | 6 ^{†} | 14 ^{†} | 18 ^{†} | 6 | 12 ^{†} | 10 | 4 | 16 ^{†} | 12 ^{†} |

Problem-solving | 0 ^{†} | 2 ^{†} | 0 ^{†} | 0 ^{†} | 1 | 0 ^{†} | 0 | 2 ^{†} | 2 ^{†} | 0 | 4 | 0 | 0 | 4 | 2 ^{†} | 4 | 4 | 2 | 2 | 6 ^{†} | 2 | 8 ^{†} |

Written comparison | 12 ^{†} | 10 | 12 | 12 | 14 | 18 ^{†} | 16 | 18 ^{†} | 16 | 18 ^{†} | 16 | 18 ^{†} | 18 ^{†} | 16 | 20 | 18 ^{†} | 20 | 18 ^{†} | 20 ^{†} | 20 ^{†} | 20 ^{†} | 20 ^{†} |

Zareki-R Total | 31 | 62 | 34 | 70 | 68 | 76 | 65 | 80 | 84 | 67 | 92 | 91 | 86 | 88 | 96 | 110 | 124 | 122 | 106 | 125 | 107 | 131 |

^{†}Minimal average scores.

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**Figure 2.**The four factors structure: CA= Calculation, NS= Number Sense, NC= Number Calculation, NP= Number Production.

**Figure 3.**The higher-order mathematical cognition solution (i.e., the four factors plus a mathematics cognition quotient (MC)).

**Table 1.**Range of raw score results for Zareki-R total, number of students for each per percentile and classification by age groups.

Age 7 | N (36) | Age 8 | N (81) | Age 9 | N (75) | Age 10 | N (51) | Age 11 | N (28) | Age 12 | N (33) | Percentile | Classification |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|

>138.95 | 1 | >160 | 3 | >174.8 | 4 | >176.1 | 3 | >173 | 2 | >174.35 | 1 | >95 | High |

104.2–135.0 | 8 | 144.2–159.8 | 17 | 158.0–174.2 | 15 | 165.0–175.4 | 10 | 168.1–173.0 | 5 | 165.2–172.9 | 9 | 75–94 | High average |

65.9–103.1 | 18 | 111.6–143.8 | 40 | 127.8–157.2 | 37 | 149.8–164.7 | 25 | 148.1–167.7 | 14 | 143.9–165.1 | 15 | 26–74 | Average |

48.2–64.6 | 8 | 75.5–111.2 | 17 | 85.1–127 | 15 | 125.0–149.5 | 10 | 119.6–147.5 | 6 | 131.2–143.75 | 7 | 6–25 | Low average |

<45.4 | 1 | <75.0 | 4 | <84 | 4 | <122.7 | 3 | <114.1 | 1 | <123.6 | 1 | <5 | Low |

**Table 2.**Goodness of fit statistics for each level of structural and measurement invariance across genders.

Model | χ^{2}(df) | CFI | Model Comparison | Δχ^{2} | Δdf | p | ΔCFI |
---|---|---|---|---|---|---|---|

1. Invariance of model configuration | 116.22 (62) | 0.961 | - | - | - | - | - |

2. Invariance of first-order factor loadings | 125.34 (68) | 0.959 | Model 1–Model 2 | 9.12 | 6 | 0.167 | 0.002 |

3. Invariance of intercepts | 141.78 (78) | 0.954 | Model 2–Model 3 | 16.44 | 10 | 0.088 | 0.005 |

4. Invariance of second-order factor loadings | 144.36 (81) | 0.954 | Model 3–Model 4 | 2.58 | 3 | 0.462 | 0.000 |

5. Invariance of structural variances/covariances | 150.11 (86) | 0.954 | Model 4–Model 5 | 5.75 | 5 | 0.331 | 0.000 |

6. Invariance of measurement error variances/covariances | 159.78 (96) | 0.954 | Model 5–Model 6 | 9.67 | 10 | 0.470 | 0.000 |

^{2}= chi-square test; df = degrees of freedom; CFI = robust comparative fit index; Δχ

^{2}= Satorra–Bentler scaled difference; Δdf = difference in degrees of freedom between nested models; p = probability value of Δχ

^{2}test; ΔCFI = difference between robust CFIs of nested models.

Girls (n = 143) | Boys (n = 161) | Age 7 (n = 36) | Age 8 (n = 81) | Age 9 (n = 75) | Age 10 (n= 51) | Age 11 (n = 28) | Age 12 (n= 33) | F _{(5398)} | p | η_{p}^{2} | |
---|---|---|---|---|---|---|---|---|---|---|---|

Counting dots | 3.44 (0.77) | 3.42 (0.83) | 3.36 (0.93) | 3.21 (0.86) | 3.37 (0.78) | 3.61 (0.69) | 3.68 (0.67) | 3.70 (0.64) | 3.24 | 0.007 | 0.05 |

Counting backwards ^{a} | 2.99 (1.25) | 3.08 (1.18) | 2.03 (1.36) | 2.84 (1.34) | 3.05 (1.21) | 3.57 (0.73) | 3.50 (0.88) | 3.36 (0.82) | 9.88 | <0.001 | 0.14 |

Dictation of numbers ^{b} | 12.59 (4.29) | 13.42 (3.74) | 6.33 (3.90) | 12.48 (3.60) | 13.66 (3.66) | 15.28 (1.12) | 15.21 (1.26) | 14.94 (1.39) | 45.40 | <0.001 | 0.44 |

Mental calculation ^{c} | 26.54 (11.12) | 28.40 (11.65) | 12.19 (9.00) | 23. 95 (10.06) | 29.11 (10.26) | 35.26 (6.52) | 34.68 (8.85) | 31.46 (7.75) | 35.16 | <0.001 | 0.37 |

Reading numbers ^{d} | 13.66 (3.77) | 14.32 (3.45) | 7.92 (4.63) | 13.72 (3.22) | 14.65 (2.84) | 15.78 (0.67) | 15.93 (0.38) | 15.55 (1.06) | 45.72 | <0.001 | 0.43 |

Memory of Digits | 23.44 (6.21) | 23.56 (6.57) | 21.34 (5.64) | 23.63 (6.72) | 22.59 (5.71) | 24.90 (6.90) | 23.86 (6.88) | 25.21 (6.02) | 2.16 | <0.06 | 0.03 |

Positioning numbers^{e} | 16.04 (5.06) | 16.61 (4.85) | 11.13 (5.88) | 15.93 (4.67) | 16.81 (5.25) | 18.28 (2.91) | 17.95 (3.82) | 17.65 (3.01) | 13.00 | <0.001 | 0.18 |

Oral comparison ^{f} | 13.23 (2.84) | 14.06 (2.45) | 10.92 (3.42) | 12.52 (2.88) | 14.52 (1.83) | 14.57 (1.66) | 15.04 (1.23) | 15.00 (1.50) | 22.24 | <0.001 | 0.27 |

Perceptual estimation | 6.10 (2.27) | 6.71 (2.29) | 5.50 (2.36) | 6.05 (2.36) | 6.56 (2.41) | 6.90 (2.05) | 6.54 (1.90) | 7.21 (2.13) | 2.97 | 0.01 | 0.05 |

Contextual estimation ^{g} | 11.80 (4.89) | 11.90 (5.11) | 8.39 (3.99) | 10.05 (4.53) | 11.39 (5.00) | 14.12 (4.81) | 14.21 (3.86) | 15.64 (3.41) | 15.98 | <0.001 | 0.21 |

Problem-solving ^{h} | 6.41 (3.91) | 7.56 (3.92) | 2.81 (3.25) | 5.30 (3.57) | 7.81 (3.97) | 8.92 (2.63) | 9.14 (2.86) | 9.30 (2.47) | 25.32 | <0.001 | 0.30 |

Written comparison ^{j} | 18.73 (2.12) | 18.88 (2.14) | 16.72 (3.03) | 18.57 (2.49) | 19.05 (1.32) | 19.49 (1.59) | 19.57 (0.84) | 19.39 (1.37) | 11.21 | <0.001 | 0.16 |

Zareki-R Total ^{c} | 140.27 (38.52) | 149.20 (37.68) | 87.31 (26.11) | 124.75 (25.46) | 140.00 (26.8) | 155.78 (13.87) | 155.54 (15.9) | 153.26 (15.17) | 53.47 | <0.001 | 0.47 |

Score A ^{c} | 91.16 (23.31) | 96.63 (23.46) | 56.89 (20.38) | 86.53 (19.59) | 98.80 (19.67) | 109.29 (10.42) | 109.57 (12.22) | 105.64 (11.83) | 52.97 | <0.001 | 0.47 |

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Santos, F.H.; Ribeiro, F.S.; Dias-Piovezana, A.L.; Primi, C.; Dowker, A.; von Aster, M.
Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context. *Brain Sci.* **2022**, *12*, 653.
https://doi.org/10.3390/brainsci12050653

**AMA Style**

Santos FH, Ribeiro FS, Dias-Piovezana AL, Primi C, Dowker A, von Aster M.
Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context. *Brain Sciences*. 2022; 12(5):653.
https://doi.org/10.3390/brainsci12050653

**Chicago/Turabian Style**

Santos, Flavia H., Fabiana S. Ribeiro, Ana Luiza Dias-Piovezana, Caterina Primi, Ann Dowker, and Michael von Aster.
2022. "Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context" *Brain Sciences* 12, no. 5: 653.
https://doi.org/10.3390/brainsci12050653