MSQL cálculos diretos no SELECT

SELECT cli.razao,cli.mensal_juros
,cab.registro,cab.emissao,cab.nota_total
,(DATEDIFF(CURDATE(),cab.emissao)) AS atrazo_dias
,50.00 AS juros_taxa_mes
,CAST((cab.nota_total*50.00/100)/30 AS DECIMAL(12,2)) AS juros_dia
,CAST((cab.nota_total*50.00/100)/30 AS DECIMAL(12,2))*(DATEDIFF(CURDATE(),cab.emissao)) AS total_juros
,cab.nota_total+CAST((cab.nota_total*50.00/100)/30 AS DECIMAL(12,2))*(DATEDIFF(CURDATE(),cab.emissao)) AS total_pagar
FROM cfs_cabec AS cab, cli_cadastro AS cli
WHERE cab.dest_codigo='101'
AND cab.dest_codigo=cli.registro