How to simplify 28 of 42 math problems in Grade 5 of primary school

How to simplify 28 of 42 math problems in Grade 5 of primary school

28 out of 42 = 2 out of 3
Divide by 14

How to simplify 18 out of 24 math problems in Grade 5 of primary school

3 / 4

How to simplify 30 out of 33 math problems in Grade 5 of primary school

30 out of 33
=(33 / 3) (30 / 3)
=10 out of 11
Do not understand welcome to ask

1×1 + 2×2 + 3×3 + …… + 2002×2002 = 2676679005,
Find 1 × 2 + 2 × 3 + 3 × 4 + + 2002×2003

1×2 + 2×3 + 3×4 + …… + 2002×2003=1×(1+1)+2×(2+1)+3×(3+1)+…… + 2002×(2002+1)=1×1 + 2×2 + 3×3 + …… + 2002×2002+1+2+3+ …… + 2002=2676679005+2005003=2678684008