example.tsx

useEffect(() => {
    const durationMs = parseDuration(duration ?? '');

    if (durationMs && selectedToken) {
      const durationSeconds = new Decimal(durationMs).div(1000);
      const speedInYocto = new Decimal(amountToStream)
        .div(durationSeconds)
        .toFixed();

      setValue('speed', speedInYocto);
    } else {
      setValue('speed', '0');
    }
  }, [setValue, duration, amountToStream, selectedToken]);

  const speedInHuman = useMemo(() => {
    if (selectedToken && speed !== '0') {
      const formatter = new TokenFormatter(selectedToken.decimals);

      return formatter.tokensPerMeaningfulPeriod(speed);
    }

    return { formattedValue: '0', unit: 'second' };
  }, [speed, selectedToken]);