Table 4.
Standardized estimates and explained variance (R 2) of visual-spatial (VS) working memory and verbal (VE) working memory from multilevel regression model to predict intercept and slope in math fluency, and difference between standardized estimates (Z H)
| intercept | slope | ||||||
|---|---|---|---|---|---|---|---|
| VS | VE | R 2 | Z H a | VS | VE | R 2 | |
| Addition | |||||||
| Overall model | .33*** | .31*** | .31*** | - | .02 | -.00 | .00 |
| Grade 2 | .14** | .14* | .05* | 0.0 | .14** | -.00 | .02 |
| Grade 3 | .18*** | .19*** | .08*** | -0.2 | -.01 | -.01 | .00 |
| Grade 4 | .16** | .16** | .07* | 0.0 | .06 | .04 | .01 |
| Grade 5 | .10 | .24*** | .08** | -3.8*** | - | - | - |
| Grade 6 | -.01 | .28*** | .07** | -8.2*** | - | - | - |
| Subtraction | |||||||
| Overall model | .33*** | .33*** | .32*** | - | -.14 | -.00 | .02 |
| Grade 2 | .14** | .20** | .07** | -1.4 | .03 | .16* | .03 |
| Grade 3 | .22*** | .22*** | .12*** | 0.0 | -.02 | .04 | .00 |
| Grade 4 | .18** | .21*** | .11** | -0.8 | - | - | - |
| Grade 5 | .08 | .25*** | .09*** | -4.6*** | - | - | - |
| Grade 6 | .05 | .29*** | .10** | -6.8*** | - | - | - |
| Multiplication | |||||||
| Overall model | .24*** | .27*** | .19*** | - | -.05 | -.00 | .00 |
| Grade 3 | .18*** | .10* | .05** | 1.9 | .09 | -.01 | .01 |
| Grade 4 | .10 | .13* | .04 | -0.8 | -.09 | .18 | .03 |
| Grade 5 | .05 | .17*** | .04* | -3.2** | .14 | -.07 | .02 |
| Grade 6 | -.02 | .24*** | .05** | -7.3*** | .02 | .19 | .04 |
| Division | |||||||
| Overall model | .28*** | .30*** | .26*** | - | -.08 | .03 | .00 |
| Grade 3 | .22*** | .15** | .09** | 1.7 | .04 | .02 | .00 |
| Grade 4 | .17*** | .17*** | .08** | 0.0 | .03 | .11 | .01 |
| Grade 5 | .13* | .21*** | .08** | -2.5* | .01 | .05 | .00 |
| Grade 6 | .06 | .29*** | .10*** | -6.6*** | -.02 | .23 | .05 |
Two-sided p-values: *** p < .001, ** p < .01, * p < .05
aHolm’s correction for multiple comparisons has been applied