Use the following numbers to calculate the net federal tax (line 42000):
Total income (line 15000) : $51,000
Total at line 23300 : $2,500
Total federal non-refundable tax credits (line 35000) : $3,285
Assume the year of 2019. So federal tax rate is 20.5%; and Step 5 - Federal Tax (formerly Schedule 1) Line 37 & 41 is $47,630 & $7,145 respectively.