Strong's numbers

δικαιόω G1344

dikaióō

dik-ah-yo'-o

from δίκαιος; to render (i.e. show or regard as) just or innocent:--free, justify(-ier), be righteous.

δικαιόω, -ῶ (< δίκαιος), [in LXX chiefly for צדק pi., hi., (1) as Ez 16:51, Je 3:11 (cf. NT usage); (2) as De 25:1; Ex 23:7, Is 50:8 ;]

1. in cl.,

(a) c. acc rei, to deem right;

(b) c. acc pers., to do one justice; pass., δικαιοῦσθαι, to be treated rightly, opp. to ἀδικεῖσθαι.

2. In NT, as in LXX, and as usual with verbs in -όω from adjectives of moral meaning;

(1) to show to be righteous: Mt 11:19, Lk 7:35, Ro 3:4 (LXX), I Ti 3:16;

(2) to declare, pronounce righteous: Lk 7:29 10:29 16:15 18:14, Ro 2:13 3:24, 26, 28 4:5 8:30, 33, Tit 3:7; seq. ἀπό, Mt 11:19, Lk 7:35, Ac 13:39, Ro 6:7; ἐκ πίστεως, Ro 3:30 5:1, Ga 2:16 3:8, 24; ἐξ ἔργων, Ro 3:20 (LXX) 4:2, Ga 2:16, Ja 2:21, 24, 25; ἐκ τ. λόγων, Mt 12:37; διὰ τ. πίστεως, Ro 3:30; c. dat., Ro 3:24, 28, Tit 3:7; seq. ἐν, Ac 13:39, Ro 3:4 5:9, I Co 4:4 6:11, Ga 2:17 3:11 5:4, I Ti 3:16 (v. Cremer, 193, 693; DB, ii, 826 ff.).†

From G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), in the public domain.

Shown in the King James Version (KJV), whichever translation you read in — it is the text these numbers are tagged against.

Romans 3:20
Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
Romans 3:24
Being justified freely by his grace through the redemption that is in Christ Jesus:
Romans 3:26
To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
Romans 3:28
Therefore we conclude that a man is justified by faith without the deeds of the law.
Romans 3:30
Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
Romans 4:2
For if Abraham were justified by works, he hath whereof to glory; but not before God.
Romans 4:5
But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.
Romans 5:1
Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:
Romans 5:9
Much more then, being now justified by his blood, we shall be saved from wrath through him.
Romans 6:7
For he that is dead is freed from sin.